Major interaction on record — check this product against your medications before combining. Based on 7 of 10 ingredients. Check your meds →
Dietary supplement

Lipo 6X Ingredients & Drug Interactions

by Nutrex Research

Lipo 6X label
See full label image
Capsule Category: Non-nutrient/non-botanical
Most serious interaction: Major
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Lipo 6X against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Major

Lipo 6X is a dietary supplement by Nutrex Research with 10 active ingredients. Its ingredients are commonly taken for mental alertness and reducing fatigue, improving athletic performance, headache and migraine relief.Based on those ingredients, 1,334 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Yohimbe, Synephrine, Caffeine Anhydrous. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Lipo 6X by Nutrex Research

Ask about any prescription or over-the-counter medication and we check it for interactions with Lipo 6X by Nutrex Research — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
Prefer a human? Send your question to our licensed pharmacists — free, answered by email within 24 hours.

HelloPharmacist Scorecard of Lipo 6X by Nutrex Research

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Aug 13, 2026

What’s inside

Low disclosure
Ingredient Transparency · database check
Low

Most active ingredients don't disclose an individual amount — you can't tell how much of each you're getting.

Why this rating?
  • The label discloses an exact amount for 4 of its 10 active ingredients.
  • “Phase#1 Rapid Release Liquid Delivery Blend” is a proprietary blend — the label gives one combined amount (806 mg) without saying how much of each component you get.
  • “Synthetic Thermogenesis Activating Complex” is a proprietary blend — the label gives one combined amount (100 mg) without saying how much of each component you get.

Lipo 6X contains 10 active ingredients formulated as a weight-loss and energy supplement. The main components are caffeine anhydrous (a stimulant for mental alertness and athletic performance), yohimbe (an herbal extract with limited evidence for its claimed uses), synephrine from bitter orange (a stimulant with cardiovascular effects), hordenine (structurally similar to stimulants but unstudied in humans), tyramine (a compound that affects blood pressure), and phenethylamine or B-phenylethylamine (a compound with limited human safety data).

The product also includes glycerin (which is generally well tolerated but can cause bloating or diarrhea at higher doses) and three proprietary blends whose exact dosages are not disclosed: a Phase #1 rapid-release liquid delivery blend, a synthetic thermogenesis activating complex, and synthetic guggulsterones. The capsule is made with vegetable cellulose and contains inactive ingredients including polysorbate 80, vegetable cellulose, and FD&C Blue #2 dye.

Does it work?

Strong evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Strong

Clinical evidence supports at least one of this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: fat burning and energy with appetite suppression.
  • We looked for evidence on: Athletic performance, Fatigue, Mental alertness, Obesity, Metabolic rate, Energy expenditure.
  • The strongest evidence on file: Caffeine is rated "Likely Effective" for Athletic performance (Natural Medicines).
  • Also on file: Caffeine is rated "Likely Effective" for Mental alertness.
  • Also on file: Glycerol is rated "Possibly Effective" for Athletic performance.

The evidence for most of Lipo 6X's ingredients is weak or absent. Caffeine is likely effective for mental alertness and athletic performance.

Glycerin is likely effective for constipation, though that's not the product's stated purpose. All other ingredients—yohimbe, synephrine, hordenine, tyramine, phenethylamine, and the proprietary blends—have either insufficient reliable evidence or no established effectiveness rating in our data for weight loss, fat loss, or the athletic performance claims on a fat-loss product.

In short, you're paying mainly for caffeine and untested stimulants.

The evidence, ingredient by ingredient Caffeine Yohimbe Bitter Orange Glycerol Hordenine Tyramine Phenethylamine (pea)

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 7 of the 7 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 6 of 7.
  • General safety write-ups exist for 7 of 7.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Caffeine in moderate doses is generally well tolerated for healthy adults, but high amounts in this product—combined with other stimulants like yohimbe, synephrine, and hordenine—create a serious cardiovascular risk. Common side effects from the stimulant blend include anxiety, jitteriness, insomnia, diarrhea, nausea, headache, tremors, and elevated heart rate and blood pressure.

Yohimbe carries particular caution: it can cause hypertension, tachycardia, anxiety, agitation, and tremors, and rare cases of hypertensive crisis have been reported. Synephrine (bitter orange) can raise blood pressure and heart rate, especially with caffeine, and serious but rare complications including heart attack, stroke, seizure, and abnormal heartbeat have been documented.

Glycerin at normal supplement doses may cause bloating, nausea, diarrhea, or dizziness. Tyramine, even at supplement doses, can elevate blood pressure and cause headache or dizziness.

For pregnancy, yohimbe is considered unsafe and synephrine is possibly unsafe—avoid this product entirely if you're pregnant or breastfeeding. Caffeine passes into breast milk in small amounts; the combination of stimulants here makes breastfeeding inadvisable.

Side effects, ingredient by ingredient Caffeine Yohimbe Bitter Orange Glycerol Hordenine Tyramine Phenethylamine (pea)

Meds to double-check

Major interaction found
Known Interaction Concern · database check
Major identified

At least one ingredient has a documented Major-severity interaction. Check your medications for a personalized result.

Why this rating?
  • 6 of the 7 matched ingredients can interact with medications — Yohimbe, Bitter Orange, Caffeine, Phenethylamine (pea), Hordenine, among others.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; diabetes medications; heart-rhythm medications; lithium.
  • For scale: 1,335 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before taking Lipo 6X, double-check with your doctor or pharmacist if you take MAOIs (Major-severity interactions with multiple ingredients), ephedrine (Major-severity stimulant danger), midazolam or other sedatives (Major-severity with synephrine), any blood pressure medication (Moderate with yohimbe and tyramine, Major with tyramine), seizure medications like phenobarbital or carbamazepine (Moderate with caffeine), antipsychotics like clozapine (Moderate with caffeine), tricyclic antidepressants like amitriptyline (Moderate with yohimbe), serotonin-boosting antidepressants (Moderate with phenethylamine), barbiturates, quinolone antibiotics, cimetidine, or diabetes drugs. If you take any stimulant (prescription or supplement), the additive risk is Moderate but very real.

No interactions are documented for the ingredients we could not check (N-Methyl-Beta-Phenylethylamine, synthetic guggulsterones, or purified water), but that does not mean they are safe to combine with your medications.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFormula with limited ingredient disclosure with clinical evidence supporting its stated purpose. Major medication interactions have been identified, and safety information is well characterized.

Lipo 6X is a stimulant-heavy fat-loss product with significant medication interactions and unproven active ingredients beyond caffeine. If you take any blood pressure medication, heart drug, antidepressant, seizure medication, diabetes drug, or MAOI, do not start this product without clearing it first with your own doctor or pharmacist—the interaction risks are real.

Even without those medications, the combination of yohimbe, synephrine, hordenine, and high-dose caffeine can cause serious cardiovascular strain. Pregnancy and breastfeeding are off-limits.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 7 of 10 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Feb 26, 2014.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Lipo 6X, straight from the product label.

Brand Nutrex Research
Barcode (UPC) 853237000288
Net contents 240 Multi-Phase Capsule(s)
Market status On market
Date entered into DSLD Feb 26, 2014
DSLD ID 30182
Product type Non-nutrient/non-botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years)
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Lipo 6X by Nutrex Research, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
2 Multi-Phase Capsule(s)
Maximum serving Sizes:
2 Multi-Phase Capsule(s)
Servings per container
120
UPC/BARCODE
853237000288
IngredientAmount% DV
Glycerin0 Not Present--
Caffeine Anhydrous200 mg--
Yohimbe3 mg--
Synephrine20 mg--
Hordenine0 Not Present--
Tyramine0 Not Present--
B-Phenylethylamine0 Not Present--
N-Methyl-Beta-Phenylethylamine0 Not Present--
Synthetic Guggulsterones Z&E 1:120 mg--
Purified USP Water0 Not Present--
Phase#1 Rapid Release Liquid Delivery Blend806 mg--
Synthetic Thermogenesis Activating Complex100 mg--

Other ingredients: Polysorbate 80, Vegetable Cellulose, FD&C Blue #2

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
General Statements

MULTI-PHASE Technology LIPO-6X is a powerful fat burner using a superior MULTI-PHASE technology. MULTI-PHASE technology combines rapid liquid capsule delivery with extended-release inside capsule technology. What this means is that LIPO-6X is a fat burner that has multiple release phases, both fast and extended.

Phase #1 Rapid Release Liquid Capsule: The outer liquid capsule of LIPO-6X ensures a rapid uptake of its appetite-suppressing, fat-burning and energy-promoting ingredients. Within minutes of taking LIPO-6 you will feel it working.

Phase #2 Extended-Release Inside Capsule: LIPO-6X continues to work over an extended period of time thanks to the slower release second capsule that sits inside the liquid capsule. Due to its delayed absorption the inside capsule extends the amount of time LIPO-6X is active.

LIPO-6X offers speed and duration. A rapid onset of its fat-burning and energy-promoting effects, combined with an extended-release, will help ensure maximum results.

Use your smart phone to scan this QR code and see real consumer reviews about this product. Or visit Nutrex.com

MULTI-PHASE TECHNOLOGY

TWO-PHASE RELEASE BURN FAT FAST!

LIPO-6X is best used in cycles. The suggested cycle length is 8 weeks followed by a 1 week break.

LIPO-6X is best used in cycles. The suggested cycle length is 8 weeks followed by a 1 week break.

Actual capsules may differ in appearance from capsule shown on label.

General

LBL-LIPO6X-240CT-V3-US

FDA Statement of Identity

Dietary Supplement

Suggested/Recommended/Usage/Directions

RECOMMENDED USE TO BURN FAT FAST: Start off with only 2 multi-phase capsules on your first two days (1 in the morning and 1 in the afternoon) and increase dosage by 1 multi-phase capsule every two days until maximum dosage of 4 multi-phase capsules per day is reached. From here on take 2 multi-phase capsules in the morning and an additional 2 multi-phase capsules in the afternoon. DO NOT EXCEED 4 MULTI-PHASE CAPSULES PER DAY. Do not take within 6 hours of sleep.

For optimum results LIPO-6X should not be taken with meals. Consume at least 30 minutes before a meal.

Precautions

WARNING: LIPO-6X is not for use by persons under the age of 18.

Do not use if pregnant or nursing.

Do not exceed recommended dosage.

Do not consume synephrine, caffeine or thyroid-boosting compounds from other sources, including but not limited to, coffee, tea, soda and other dietary supplements or medications containing Phenylephrine or caffeine.

Consult your physician prior to use if you are taking medications, including but not limited to, MAOI inhibitors, anti-depressants, aspirin, non-steroidal anti-inflammatory drugs or products containing phenylephrine, ephedrine, pseudoephedrine, or other stimulants.

Consult your physician prior to use if you have a medical condition, including but not limited to heart, liver, kidney or thyroid disease, psychiatric disorders, difficulty urinating, diabetes, high blood pressure, cardiac arrhythmia, recurrent headaches, enlarged prostate, or glaucoma. Discontinue 2 weeks prior to surgery. Immediately discontinue if you experience rapid heart beat, dizziness, severe headaches or shortness of breath.

This product contains ingredients that may be banned by some sports organizations.

KEEP OUT OF REACH OF CHILDREN.

Formula

This product contains caffeine.

FDA Disclaimer Statement

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose,treat, cure, or prevent any disease.

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Lipo 6X by Nutrex Research label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Lipo 6X label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Lipo 6X by Nutrex Research

These are the 10 active ingredients this product is made of. Select any to open its full monograph.

Serving size2 Multi-Phase Capsule(s) Dosage formCapsule Servings per container120 Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

Caffeine Anhydrous

Interacts with
655 drugs
200 mg per serving

Caffeine is a natural stimulant found in coffee, tea, and many other plants and products. In moderate amounts it can boost alertness and reduce tiredn...

Caffeine Anhydrous monograph & interactions

Yohimbe

Interacts with
1,125 drugs
3 mg per serving

Yohimbe is a West African tree bark that contains yohimbine, a compound mainly promoted for erectile dysfunction and as an aphrodisiac. A prescription...

Yohimbe monograph & interactions

Synephrine

Interacts with
957 drugs
20 mg per serving

Bitter orange is a citrus fruit whose extracts contain synephrine, a mild stimulant often added to weight-loss and energy supplements. Evidence that i...

Synephrine monograph & interactions

Synthetic Guggulsterones Z&E 1:1

20 mg per serving

Phase#1 Rapid Release Liquid Delivery Blend

806 mg per serving

Synthetic Thermogenesis Activating Complex

100 mg per serving

Other (inactive) ingredients: Polysorbate 80, Vegetable Cellulose, FD&C Blue #2. These complete the product’s ingredient list but are not active constituents.

Interaction report

Lipo 6X by Nutrex Research Drug Interactions

Want to check YOUR meds against Lipo 6X?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
1,334Drugs
190 Major 1,118 Moderate 26 Minor

Ingredients driving the most interactions

Yohimbe 1,125
Synephrine 957
Caffeine Anhydrous 655
Tyramine 353
Hordenine 329

Individual Drug Interactions

The ingredients in Lipo 6X interact with 1,334 drugs. Click any drug to see the details.

6 of the 10 ingredients in Lipo 6X interact with drugs. Each result below shows which ingredient is responsible. Yohimbe Synephrine Caffeine Anhydrous Tyramine Hordenine B-Phenylethylamine

Each ingredient & the kinds of drugs it affects

For each ingredient in Lipo 6X with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.

Yohimbe13 drug types · 1,125 drugs

Monoamine Oxidase Inhibitors (Maois)

Concomitant use of MAOIs with yohimbe can result in additive effects.
Yohimbine, a constituent of yohimbe, has MAO inhibitory effects. At high doses, yohimbine is a non-selective inhibitor of MAO.

Likelihood Likely Evidence D
Antihypertensive Drugs

Theoretically, yohimbe might reduce the effects of antihypertensive drugs.
Yohimbine, a constituent of yohimbe, is an alpha-2 adrenoceptor antagonist and has been reported to increase blood pressure in clinical research. Theoretically, concomitant use of yohimbe and antihypertensive drugs can interfere with blood pressure control.

Likelihood Probable Evidence D
Clonidine (Catapres)

Theoretically, yohimbe might precipitate clonidine withdrawal.
Chronic clonidine use can downregulate alpha-2 adrenoreceptors. Animal research and one human case report suggest that concomitant administration of yohimbine, an alpha-2 adrenoceptor antagonist, may precipitate clonidine withdrawal and lead to sympathomimetic toxicity, including hypertensive crisis.

Likelihood Possible Evidence D
Cytochrome P450 2D6 (Cyp2D6) Inhibitors

CYP2D6 inhibitors may increase the levels and adverse effects of yohimbine, a constituent of yohimbe.
In vitro and clinical research shows that the yohimbe bark constituent, yohimbine, is metabolized by CYP2D6 isoenzymes. Paroxetine, a cytochrome P450 (CYP) 2D6 inhibitor, increases the maximum serum concentration of yohimbine and reduces the clearance of yohimbine compared to yohimbine alone in patients who are extensive CYP2D6 metabolizers..

Likelihood Probable Evidence B
Cytochrome P450 2D6 (Cyp2D6) Substrates

Theoretically, yohimbe might increase the levels and adverse effects of CYP2D6 substrates.
In vitro research suggests that yohimbine, a constituent of yohimbe bark, inhibits CYP2D6 enzyme activity.

Likelihood Possible Evidence D
Cytochrome P450 3A4 (Cyp3A4) Inhibitors

Theoretically, CYP3A4 inhibitors might increase the levels and adverse effects of yohimbine, a constituent of yohimbe bark.
In vitro and clinical research shows that the yohimbe bark constituent, yohimbine, is metabolized by CYP3A4 enzymes. Theoretically, drugs that inhibit CYP3A4 might increase the levels and adverse effects of yohimbine.

Likelihood Possible Evidence D
Paroxetine (Paxil)

Paroxetine decreases the clearance of yohimbine and may increase its effects.
Paroxetine, a cytochrome P450 (CYP) 2D6 inhibitor, increases the maximum serum concentration of yohimbine by about 350% and reduces the clearance of yohimbine by about 80% compared to yohimbine alone in patients who are extensive CYP2D6 metabolizers. No significant changes in pharmacokinetic parameters of yohimbine were observed with coadministration of paroxetine in patients who are poor CYP2D6 metabolizers.

Likelihood Probable Evidence B
Phenothiazines

Theoretically, using yohimbine with phenothiazines might have additive effects.
Yohimbine, a constituent of yohimbe, has alpha-2 adrenergic antagonist effects. Theoretically, combining it with phenothiazines can cause additive alpha-2 adrenergic antagonism.

Likelihood Possible Evidence D
Stimulant Drugs

Theoretically, taking yohimbe with stimulant drugs can have additive effects.
Yohimbine, a constituent of yohimbe, has sympathomimetic effects and increases blood pressure in a dose-dependent manner. Theoretically, taking yohimbe with stimulant drugs can have additive stimulant and hypertensive effects.

Likelihood Possible Evidence D
Tricyclic Antidepressants (Tcas)

Theoretically, taking yohimbe with TCAs can increase adverse effects.
A small clinical study in patients taking TCAs for at least 4 weeks shows that receiving doses of intravenous yohimbine 2.5-20 mg daily for up to 7 days precipitates severe anxiety, agitation, and tremor. The effects of yohimbe bark itself are unclear; oral yohimbe bark contains 0.6% to 1.38% yohimbine, but it is unclear how much is absorbed.

Likelihood Possible Evidence D
Anticoagulant/Antiplatelet Drugs

Theoretically, combining yohimbe bark with antiplatelet or anticoagulant drugs might have additive effects; however, this has not been reported in clinical research.
Research in healthy adults shows that taking yohimbine, a constituent of yohimbe bark, in doses of 8 mg or more, seems to inhibit platelet aggregation in vitro by binding to the alpha-2 adrenoceptor. The effects of yohimbe bark itself are unclear; yohimbe bark contains 0.6% to 1.38% yohimbine, but it is unclear how much is absorbed.

Likelihood Possible Evidence D
Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, yohimbe might decrease the levels and clinical effects of CYP1A2 substrates.
In vitro research shows that yohimbe extract induces CYP1A2 enzymes.

Likelihood Possible Evidence D
Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, yohimbe might decrease the levels and clinical effects of CYP3A4 substrates.
In vitro research shows that yohimbe extract induces CYP3A4 enzymes.

Likelihood Possible Evidence D
Yohimbe full monograph & interactions

Synephrine13 drug types · 957 drugs

Midazolam (Versed)

Bitter orange might increase blood levels of midazolam.
One small clinical study shows that bitter orange juice can increase midazolam levels, likely through inhibition of cytochrome P450 3A4 (CYP3A4). Theoretically, bitter orange might increase the risk of midazolam-related adverse effects.

Likelihood Probable Evidence B
Monoamine Oxidase Inhibitors (Maois)

Theoretically, taking MAOIs with synephrine-containing bitter orange preparations might increase the hypertensive effects of synephrine, potentially leading to hypertensive crisis.
Bitter orange contains tyramine, octopamine, and synephrine, which are MAO substrates.

Likelihood Probable Evidence D
Antidiabetes Drugs

Theoretically, bitter orange might increase the risk of hypoglycemia when taken with antidiabetes drugs.
Some clinical research shows that drinking a tea containing bitter orange and Indian snakeroot reduces fasting and postprandial glucose levels in patients with type 2 diabetes who are using antidiabetes drugs. However, it is unclear if these effects are due to bitter orange, Indian snakeroot, or the combination. An animal study also shows that p-synephrine in combination with gliclazide , a sulfonylurea, causes an additional 20% to 44% decrease in glucose levels when compared with gliclazide alone.

Likelihood Possible Evidence B
Caffeine

Bitter orange might increase blood pressure and heart rate when taken with caffeine.
Small clinical studies show that taking bitter orange in combination with caffeine can increase blood pressure and heart rate in otherwise healthy normotensive adults. Theoretically, this might increase the risk of serious cardiovascular adverse effects.

Likelihood Possible Evidence B
Colchicine

Bitter orange might affect colchicine levels.
Colchicine is a substrate of P-glycoprotein and cytochrome P450 3A4 (CYP3A4). Bitter orange has been reported to inhibit CYP3A4 and increase levels of CYP3A4 substrates. However, one small clinical study in healthy adults shows that drinking bitter orange juice 240 mL twice daily for 4 days and taking a single dose of colchicine 0.6 mg on the 4th day decreases colchicine peak serum levels by 24%, time to peak serum level by 1 hour, and overall exposure to colchicine by 20%. The clinical significance of this finding is unclear.

Likelihood Possible Evidence B
Cytochrome P450 3A4 (Cyp3A4) Substrates

Bitter orange might increase levels of drugs metabolized by CYP3A4.
Small clinical studies suggest that single or multiple doses of freshly squeezed bitter orange juice 200-240 mL can inhibit CYP3A4 metabolism of drugs, causing increased drug levels and potentially increasing the risk of adverse effects. However, the extent of the effect of bitter orange on CYP3A4-mediated drug interactions is unknown. Some evidence suggests that bitter orange selectively inhibits intestinal CYP3A4, but not hepatic CYP3A4. Its effect on P-glycoprotein, which strongly overlaps with CYP3A4 interactions, is unclear. One small clinical study shows that drinking 8 ounces of freshly squeezed bitter orange juice has no effect on cyclosporine, which seems to be more dependent on hepatic CYP3A4 and P-glycoprotein than intestinal CYP3A4.

Likelihood Possible Evidence B
Dextromethorphan (Robitussin Dm, Others)

Bitter orange might increase blood levels of dextromethorphan.
One small clinical study shows that bitter orange juice increases dextromethorphan levels, likely through cytochrome P450 3A4 (CYP3A4) inhibition. Theoretically, bitter orange might increase the risk for dextromethorphan-related adverse effects.

Likelihood Possible Evidence B
Felodipine (Plendil)

Bitter orange might increase blood levels of felodipine.
One small clinical study shows that bitter orange juice increases felodipine levels, likely through cytochrome P450 3A4 (CYP3A4) inhibition. Theoretically, bitter orange might increase the risk for felodipine-related adverse effects.

Likelihood Probable Evidence B
Indinavir (Crixivan)

Bitter orange might increase blood levels of indinavir.
One small clinical study shows that bitter orange juice slightly increases indinavir levels, but this effect is likely to be clinically insignificant. Bitter orange selectively inhibits intestinal cytochrome P450 3A4 (CYP3A4); however, the metabolism of indinavir seems to be more dependent on hepatic CYP3A4. The effect of bitter orange on other protease inhibitors has not been studied.

Likelihood Possible Evidence B
Qt Interval-Prolonging Drugs

Theoretically, bitter orange might have an additive effect when combined with drugs that prolong the QT interval, potentially increasing the risk of ventricular arrhythmias.
One case report suggests that taking bitter orange in combination with other stimulants such as caffeine might prolong the QT interval in some patients.

Likelihood Possible Evidence D
Sildenafil (Viagra)

Bitter orange juice might increase blood levels of sildenafil.
A small clinical study in healthy adult males shows that drinking freshly squeezed bitter orange juice 250 mL daily for 3 days and taking a single dose of sildenafil 50 mg on the 3rd day increases the peak plasma concentration of sildenafil by 18% and the overall exposure to sildenafil by 44%. Theoretically, this may be due to inhibition of cytochrome P450 3A4 by bitter orange.

Likelihood Probable Evidence B
Stimulant Drugs

Theoretically, bitter orange might increase the risk of hypertension and adverse cardiovascular effects when taken with stimulant drugs.
Bitter orange appears to have stimulant effects.

Likelihood Possible Evidence B
Cytochrome P450 2D6 (Cyp2D6) Substrates

Theoretically, bitter orange might increase levels of drug metabolized by CYP2D6.
In vitro research shows that octopamine, a constituent of bitter orange, weakly inhibits CYP2D6 enzymes. This effect has not been reported in humans.

Likelihood Possible Evidence D
Synephrine full monograph & interactions

Caffeine Anhydrous41 drug types · 655 drugs

Ephedrine

Theoretically, concomitant use might increase the risk for stimulant adverse effects.
Use of ephedrine with caffeine can increase the risk of stimulatory adverse effects. There is evidence that using ephedrine with caffeine might increase the risk of serious life-threatening or debilitating adverse effects such as hypertension, myocardial infarction, stroke, seizures, and death.

Likelihood Probable Evidence D
Adenosine (Adenocard)

Theoretically, caffeine might decrease the vasodilatory effects of adenosine and interfere with its use prior to stress testing.
Some evidence shows that caffeine is a competitive inhibitor of adenosine and can reduce the vasodilatory effects of adenosine in humans. However, other research shows that caffeine does not seem to affect supplemental adenosine because high interstitial levels of adenosine overcome the antagonistic effects of caffeine. It is recommended that methylxanthines and methylxanthine-containing products be stopped 24 hours prior to pharmacological stress tests. However, methylxanthines appear more likely to interfere with dipyridamole (Persantine) than adenosine-induced stress testing.

Likelihood Possible Evidence B
Anticoagulant/Antiplatelet Drugs

Theoretically, caffeine may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Caffeine is reported to have antiplatelet activity. Theoretically, it might increase the risk of bleeding when used concomitantly with these agents; however, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Beta-Adrenergic Agonists

Theoretically, large amounts of caffeine might increase the cardiac inotropic effects of beta-agonists.

Likelihood Probable Evidence D
Carbamazepine (Tegretol)

Theoretically, caffeine might reduce the effects of carbamazepine and increase the risk for convulsions.
Animal research suggests that taking caffeine can lower the anticonvulsant effects of carbamazepine and can induce seizures when taken in doses above 400 mg/kg. Human research has shown that taking caffeine 300 mg in three divided doses along with carbamazepine 200 mg reduces the bioavailability of carbamazepine by 32% and prolongs the plasma half-life of carbamazepine 2-fold in healthy individuals.

Likelihood Possible Evidence D
Cimetidine (Tagamet)

Theoretically, cimetidine might increase the levels and adverse effects of caffeine.
Cimetidine decreases the rate of caffeine clearance by 31% to 42%.

Likelihood Likely Evidence B
Clozapine (Clozaril)

Caffeine might increase the levels and adverse effects of clozapine and acutely exacerbate psychotic symptoms.
Caffeine might increase the effects and toxicity of clozapine. Caffeine doses of 400-1000 mg per day inhibit clozapine metabolism. Clozapine is metabolized by cytochrome P450 1A2 (CYP1A2). Although researchers speculate that caffeine might inhibit CYP1A2, there is no reliable evidence that caffeine affects CYP1A2. There is also speculation that genetic factors might make some patients more sensitive to an interaction between clozapine and caffeine. In one case report, severe, life-threatening clozapine toxicity and multiorgan system failure occurred in a patient with schizophrenia stabilized on clozapine who consumed caffeine 600 mg daily.

Likelihood Possible Evidence B
Dipyridamole (Persantine)

Theoretically, caffeine might decrease the vasodilatory effects of dipyridamole and interfere with its use prior to stress testing.
Caffeine inhibits dipyridamole-induced vasodilation. It is recommended that methylxanthines and methylxanthine-containing products be stopped 24 hours prior to pharmacological stress tests. Methylxanthines appear more likely to interfere with dipyridamole (Persantine) than adenosine-induced stress testing.

Likelihood Probable Evidence B
Disulfiram (Antabuse)

Theoretically, disulfiram use might increase the levels and adverse effects of caffeine.
Disulfiram decreases the rate of caffeine clearance.

Likelihood Probable Evidence B
Diuretic Drugs

Theoretically, using caffeine with diuretic drugs might increase the risk of hypokalemia.
Caffeine, especially in excessive amounts, can reduce potassium levels due to stimulation of the sodium-potassium pump. Diuretics can also cause lower potassium levels.

Likelihood Possible Evidence D
Estrogens

Theoretically, estrogens might increase the levels and adverse effects of caffeine.
Estrogen inhibits caffeine metabolism.

Likelihood Probable Evidence B
Ethosuximide (Zarontin)

Theoretically, caffeine might reduce the effects of ethosuximide and increase the risk for convulsions.
Animal research suggests that caffeine 92.4 mg/kg can decrease the anticonvulsant activity of ethosuximide. However, this effect has not been reported in humans.

Likelihood Possible Evidence D
Felbamate (Felbatol)

Theoretically, caffeine might reduce the effects of felbamate and increase the risk for convulsions.
Animal research suggests that a high dose of caffeine 161.7 mg/kg can decreases the anticonvulsant activity of felbamate. However, this effect has not been reported in humans.

Likelihood Possible Evidence D
Flutamide (Eulexin)

Theoretically, caffeine might increase the levels and adverse effects of flutamide.
In vitro evidence suggests that caffeine can inhibit the metabolism of flutamide. However, this effect has not been reported in humans.

Likelihood Probable Evidence D
Fluvoxamine (Luvox)

Theoretically, fluvoxamine might increase the levels and adverse effects of caffeine.
Fluvoxamine reduces caffeine metabolism.

Likelihood Probable Evidence D
Lithium

Abrupt caffeine withdrawal might increase the levels and adverse effects of lithium.
Caffeine has diuretic activity. When abruptly discontinued, caffeine may alter the clearance of lithium. There are two case reports of lithium tremor that worsened upon abrupt coffee withdrawal and 6 case reports of elevated serum lithium levels after reducing or eliminating caffeine intake. In one case, a male with schizoaffective disorder stabilized on lithium had an elevated lithium level after reducing his caffeine intake by 87%. At a later date, he increased his caffeine intake by 6-fold, resulting in a subtherapeutic lithium level and a recurrence of psychiatric symptoms.

Likelihood Probable Evidence D
Monoamine Oxidase Inhibitors (Maois)

Theoretically, concomitant use might increase the risk of a hypertensive crisis.
Caffeine has been shown to inhibit monoamine oxidase (MAO) A and B in laboratory studies. Concomitant intake of large amounts of caffeine with MAOIs might precipitate a hypertensive crisis. In a case report, a patient that consumed 10-12 cups of caffeinated coffee and took the MAOI tranylcypromine presented with severe hypertension. Hypertension was resolved after the patient switched to drinking decaffeinated coffee.

Likelihood Possible Evidence D
Nicotine

Theoretically, concomitant use might increase the risk of hypertension.
Concomitant use of caffeine and nicotine has been shown to have additive cardiovascular effects, including increased heart rate and blood pressure. Blood pressure was increased by 10.8/12.4 mmHg when the agents were used concomitantly.

Likelihood Probable Evidence B
Pentobarbital (Nembutal)

Theoretically, caffeine might decrease the effects of pentobarbital.
Caffeine might negate the hypnotic effects of pentobarbital.

Likelihood Possible Evidence B
Phenobarbital (Luminal)

Theoretically, caffeine might reduce the effects of phenobarbital and increase the risk for convulsions.
Animal research suggests that caffeine can decrease the anticonvulsant activity of phenobarbital. However, the exact mechanism of this interaction is unclear.

Likelihood Possible Evidence D
Phenylpropanolamine

Theoretically, phenylpropanolamine might increase the risk of hypertension, as well as the levels and adverse effects of caffeine.
Concomitant use of phenylpropanolamine and caffeine might cause an additive increase in blood pressure. Phenylpropanolamine also seems to increase caffeine serum levels.

Likelihood Probable Evidence B
Phenytoin (Dilantin)

Theoretically, caffeine might reduce the effects of phenytoin and increase the risk for convulsions.
Animal research suggests that caffeine can decrease the anticonvulsant activity of phenytoin. The effect does not seem to be related to the seizure threshold-lowering effects of caffeine. However, the exact mechanism of this interaction is unclear.

Likelihood Possible Evidence D
Pioglitazone (Actos)

Theoretically, caffeine might increase the levels and clinical effects of pioglitazone.
Animal research suggests that caffeine can modestly increase the maximum concentration, area under the curve, and half-life of pioglitazone, and also reduce its clearance. This increased the antidiabetic effects of pioglitazone. However, the exact mechanism of this interaction is unclear.

Likelihood Possible Evidence D
Quinolone Antibiotics

Theoretically, quinolone antibiotics might increase the levels and adverse effects of caffeine.
Quinolones (also called fluoroquinolones) can decrease caffeine clearance by inhibiting cytochrome P450 1A2 (CYP1A2) enzyme.

Likelihood Probable Evidence B
Riluzole (Rilutek)

Theoretically, concomitant use might increase the levels and adverse effects of both caffeine and riluzole.
Caffeine and riluzole are both metabolized by cytochrome P450 1A2 (CYP1A2), and concomitant use might reduce the metabolism of one or both agents.

Likelihood Possible Evidence D
Caffeine Anhydrous full monograph & all 41 interactions

Tyramine4 drug types · 353 drugs

Antihypertensive Drugs

Tyramine may increase the risk of hypertension and reduce the effects of antihypertensive drugs.
In humans, oral and intravenous tyramine increases systolic blood pressure.

Likelihood Likely Evidence B
Monoamine Oxidase Inhibitors (Maois)

Concomitant use of tyramine with MAOIs may increase the risk of serious adverse effects from tyramine.
Tyramine is metabolized by monoamine oxidase. Concurrent use of MAOIs with tyramine can lead to elevated levels of tyramine in the body. This can increase the effects of tyramine, which has been reported to cause hypertension, headache, and hypertensive crisis in numerous cases. Sensitivity to tyramine can increase up to 10-fold to 100-fold in people using an MAOI. The European Food Safety Authority states that meals containing more than 50 mg of tyramine might present a risk to patients that are using third generation MAOI medications. Meals containing more than 6 mg of tyramine are likely to present a risk to patients who are taking classic MAOI medications.

Likelihood Likely Evidence B
Alcohol

Theoretically, concomitant use of alcohol and tyramine might increase the risk of adverse effects from tyramine.
In vitro research suggests that alcohol may potentiate the toxic effects of biogenic amines, including tyramine, possibly by decreasing their breakdown.

Likelihood Possible Evidence D
Stimulant Drugs

Theoretically, taking tyramine with stimulant drugs might increase the risk of adverse cardiovascular effects.
Tyramine is thought to have stimulant effects.

Likelihood Possible Evidence D
Tyramine full monograph & interactions

Hordenine3 drug types · 329 drugs

Monoamine Oxidase Inhibitors (Maois)

Hordenine is structurally similar to tyramine In vitro research shows that hordenine is a selective substrate for monoamine oxidase-B in the liver. Theoretically, concomitant use of hordenine with MAOIs might increase blood pressure, potentially leading to a hypertensive crisis.
Some MAOIs include isocarboxazid (Marplan), phenelzine (Nardil), selegiline (Eldepryl, Emsam, Zelapar), and tranylcypromine (Parnate).

Likelihood Possible Evidence D
Stimulant Drugs

Hordenine is structurally similar to N-methyltyramine and synephrine, constituents in bitter orange known to have stimulant properties. Theoretically, taking hordenine with drugs with stimulant properties might increase the risk of hypertension and other adverse cardiovascular effects.
Some of these drugs include amphetamine, caffeine, methylphenidate, pseudoephedrine, and many others.

Likelihood Possible Evidence D
Cytochrome P450 2D6 (Cyp2D6) Substrates

Hordenine weakly inhibits cytochrome P450 2D6 (CYP2D6) enzymes in vitro. Theoretically, hordenine might increase the levels of CYP2D6 substrates.
Some of drugs that are CYP2D6 substrates include amitriptyline (Elavil), clozapine (Clozaril), codeine, desipramine (Norpramin), donepezil (Aricept), fentanyl (Duragesic), flecainide (Tambocor), fluoxetine (Prozac), meperidine (Demerol), methadone (Dolophine), metoprolol (Lopressor, Toprol XL), olanzapine (Zyprexa), ondansetron (Zofran), tramadol (Ultram), trazodone (Desyrel), and others.

Likelihood Possible Evidence D
Hordenine full monograph & interactions

B-Phenylethylamine2 drug types · 187 drugs

Monoamine Oxidase Inhibitors (Maois)

Theoretically, taking phenethylamine concomitantly with MAOIs may increase adverse effects.
In humans, phenethylamine is oxidized by MAO-B to form the inactive metabolite phenylacetic acid. Animal research shows that administering an MAOI prior to phenethylamine increases the amphetamine-like effects of phenethylamine. However, low-quality clinical research has used phenethylamine with selegiline, an MAOI, with apparent safety.

Likelihood Possible Evidence D
Serotonergic Drugs

Theoretically, combining serotonergic drugs with phenethylamine might increase the risk of serotonergic adverse effects.
Animal research shows that phenethylamine increases levels of serotonin, norepinephrine, and dopamine. Theoretically, combining serotonergic drugs with phenethylamine might increase the risk of additive serotonergic adverse effects, including serotonin syndrome and cerebral vasoconstrictive disorders. However, low-quality clinical research has used phenethylamine with selegiline, a monoamine oxidase inhibitor (MAOI), with apparent safety.

Likelihood Possible Evidence D
B-Phenylethylamine full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Lipo 6X, from the product label.

Nutrex Research

See all Nutrex Research products
Name
Nutrex Research, Inc.
City
Oviedo
State
FL
ZipCode
32765
Phone Number
1-888-362-8739
Web Address
Nutrex.com
Pharmacist Counseling Corner

Lipo 6X by Nutrex Research: Common Questions

Does Lipo 6X by Nutrex Research interact with any medications?
Yes. Based on its ingredients, Lipo 6X has a known interaction with 1,334 medications, including 190 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Lipo 6X contains 10 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Does this product actually work for weight loss?
The evidence is weak. Caffeine is proven to help with mental alertness and athletic performance, but yohimbe, synephrine, hordenine, tyramine, and phenethylamine all have insufficient reliable evidence for weight loss or fat loss in our data. You're primarily paying for a high-dose caffeine stimulant blend.
Can I take this if I'm pregnant?
No. Yohimbe is unsafe during pregnancy, and synephrine is possibly unsafe. The combination of stimulants and lack of safety data for most ingredients makes this product a poor choice. Talk with your doctor about safer alternatives.
What are the most common side effects?
From the stimulant blend: anxiety, jitteriness, insomnia, diarrhea, nausea, headache, tremors, and elevated heart rate and blood pressure. Yohimbe can add agitation and more severe blood pressure spikes. If you're sensitive to caffeine or stimulants, this product will likely feel intense.
Is it safe to take this with my blood pressure medication?
No—not without checking first with your doctor or pharmacist. Yohimbe and tyramine can interfere with blood pressure control, and the stimulant combination can raise your pressure dangerously. This requires a professional decision based on your specific medication and health.
Can I breastfeed while taking this?
No. Caffeine passes into breast milk and can affect the baby, but more important, yohimbe is unsafe while breastfeeding and synephrine safety is not established. Avoid this product if you're nursing.
What is yohimbe and why is it in here?
Yohimbe is an herbal extract from African tree bark containing yohimbine, an ingredient with stimulant and blood-pressure-raising effects. It's included for theoretical fat-loss and energy benefits, but evidence is insufficient. It carries significant cardiovascular and interaction risks.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Not sure if Lipo 6X is safe with your meds?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Lipo 6X label
Go deeper

The Full Monographs Behind Lipo 6X’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Caffeine

Interacts with 655 drugs

Caffeine is a natural stimulant found in coffee, tea, and many other plants and products. In moderate amounts it can boost alertness and reduce tiredness for most healthy adults, but too muc...

Read the full Caffeine monograph → Herb & supplement monograph

Yohimbe

Interacts with 1,125 drugs

Yohimbe is a West African tree bark that contains yohimbine, a compound mainly promoted for erectile dysfunction and as an aphrodisiac. A prescription form of yohimbine has some evidence for...

Read the full Yohimbe monograph → Herb & supplement monograph

Bitter Orange

Interacts with 957 drugs

Bitter orange is a citrus fruit whose extracts contain synephrine, a mild stimulant often added to weight-loss and energy supplements. Evidence that it works for weight loss or performance i...

Read the full Bitter Orange monograph → Herb & supplement monograph

Glycerol

Glycerol (glycerin) is a sweet, syrupy compound made naturally in the body and widely used in foods, skin products, and medicines. It is well established as a laxative and a skin and eye moi...

Read the full Glycerol monograph → Herb & supplement monograph

Hordenine

Interacts with 329 drugs

Hordenine is a natural alkaloid found in barley and some cacti that is marketed as a stimulant for energy, focus, and fat loss, but solid human evidence for these benefits is lacking. Its sa...

Read the full Hordenine monograph → Herb & supplement monograph

Tyramine

Interacts with 353 drugs

Tyramine is a natural compound formed when certain proteins break down, and it is found in aged cheeses, cured meats, fermented foods, and some other items. It is not a typical health supple...

Read the full Tyramine monograph → Herb & supplement monograph

Phenethylamine (pea)

Interacts with 187 drugs

Phenethylamine (PEA) is a natural compound made in the body and found in foods like chocolate; supplements are marketed for mood, focus, and energy. Reliable human research on the supplement...

Read the full Phenethylamine (pea) monograph →
Sources

Sources & How We Checked

Lipo 6X's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 384 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Glycerol 8 references
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Wagner DR. Hyperhydrating with glycerol: implications for athletic performance. J Am Diet Assoc 1999;99:207-12. PubMed
  3. Yu YL, Kumana CR, Lauder IJ, et al. Treatment of acute cortical infarct with intravenous glycerol. A double-blind, placebo-controlled randomized trial. Stroke 1993;24:1119-24. PubMed
  4. Frei A, Cottier C, Wunderlich P, Ludin E. Glycerol and dextran combined in the therapy of acute stroke. A placebo-controlled, double-blind trial with a planned interim analysis. Stroke 1987;18:373-9. PubMed
  5. Balaskas E, Szepietowski JC, Bessis D, Ioannides D, Ponticelli C, Ghienne C, Taberly A, Dupuy P. Randomized, double-blind study with glycerol and paraffin in uremic xerosis. Clin J Am Soc Nephrol. 2011 Apr;6(4):748-52. PubMed
  6. Blanchet-Bardon C, Tadini G, Machado Matos M, Delarue A. Association of glycerol and paraffin in the treatment of ichthyosis in children: an international, multicentric, randomized, controlled, double-blind study. J Eur Acad Dermatol Venereol. 2012 Aug;26 PubMed
  7. Kajita N, Kanamori K, Yamamoto S, Yoshida K. Generalized Urticaria Caused by a Glycerin Enema in an Infant. J Investig Allergol Clin Immunol 2022;32(4):318-319. PubMed
  8. Suzuki R, Fukuyama K, Miyazaki Y, Namiki T. Contact urticaria syndrome and protein contact dermatitis caused by glycerin enema. JAAD Case Reports. 2016;2:108-10. PubMed

See these in context on the Glycerol monograph →

Caffeine 236 references
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Harder S, Fuhr U, Staib AH, Wolff T. Ciprofloxacin-caffeine: a drug interaction established using in vivo and in vitro investigations. Am J Med 1989;87:89S-91S. PubMed
  3. Carbo M, Segura J, De la Torre R, et al. Effect of quinolones on caffeine disposition. Clin Pharmacol Ther 1989;45:234-40. PubMed
  4. Healy DP, Polk RE, Kanawati L, et al. Interaction between oral ciprofloxacin and caffeine in normal volunteers. Antimicrob Agents Chemother 1989;33:474-8. PubMed
  5. Mester R, Toren P, Mizrachi I, et al. Caffeine withdrawal increases lithium blood levels. Biol Psychiatry 1995;37:348-50. PubMed
  6. Jefferson JW. Lithium tremor and caffeine intake: two cases of drinking less and shaking more. J Clin Psychiatry 1988;49:72-3.
  7. Joeres R, Klinker H, Heusler H, et al. Influence of mexiletine on caffeine elimination. Pharmacol Ther 1987;33:163-9. PubMed
  8. Vahedi K, Domingo V, Amarenco P, Bousser MG. Ischemic stroke in a sportsman who consumed MaHuang extract and creatine monohydrate for bodybuilding. J Neurol Neurosurg Psychiatr 2000;68:112-3.
  9. Wakabayashi K, Kono S, Shinchi K, et al. Habitual coffee consumption and blood pressure: A study of self-defense officials in Japan. Eur J Epidemiol 1998;14:669-73. PubMed
  10. Hodgson JM, Puddey IB, Burke V, et al. Effects on blood pressure of drinking green and black tea. J Hypertens 1999;17:457-63. PubMed
  11. Rapuri PB, Gallagher JC, Kinyamu HK, Ryschon KL. Caffeine intake increases the rate of bone loss in elderly women and interacts with vitamin D receptor genotypes. Am J Clin Nutr 2001;74:694-700. PubMed
  12. The National Toxicology Program (NTP). Caffeine. Center for the Evaluation of Risks to Human Reproduction (CERHR). Available at: http://cerhr.niehs.nih.gov/common/caffeine.html.
  13. Klebanoff MA, Levine RJ, DerSimonian R, et al. Maternal serum paraxanthine, a caffeine metabolite, and the risk of spontaneous abortion. N Engl J Med 1999;341:1639-44. PubMed
  14. Eskenazi B. Caffeine—filtering the facts. N Engl J Med 1999;341:1688-9. PubMed
  15. Fernandes O, Sabharwal M, Smiley T, et al. Moderate to heavy caffeine consumption during pregnancy and relationship to spontaneous abortion and abnormal fetal growth: a meta-analysis. Reprod Toxicol 1998;12:435-44. PubMed
  16. Pollock BG, Wylie M, Stack JA, et al. Inhibition of caffeine metabolism by estrogen replacement therapy in postmenopausal women. J Clin Pharmacol 1999;39:936-40. PubMed
  17. Nurminen ML, Niittynen L, Korpela R, Vapaatalo H. Coffee, caffeine and blood pressure: a critical review. Eur J Clin Nutr 1999;53:831-9. PubMed
  18. Dews PB, Curtis GL, Hanford KJ, O'Brien CP. The frequency of caffeine withdrawal in a population-based survey and in a controlled, blinded pilot experiment. J Clin Pharmacol 1999;39:1221-32. PubMed
  19. FDA. Proposed rule: dietary supplements containing ephedrine alkaloids. Available at: www.verity.fda.gov (Accessed 25 January 2000).
  20. Briggs GB, Freeman RK, Yaffe SJ. Drugs in Pregnancy and Lactation. 5th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 1998.
  21. Hagg S, Spigset O, Mjorndal T, Dahlqvist R. Effect of caffeine on clozapine pharmacokinetics in healthy volunteers. Br J Clin Pharmacol 2000;49:59-63. PubMed
  22. Tobias JD. Caffeine in the treatment of apnea associated with respiratory syncytial virus infection in neonates and infants. South Med J 2000;93:297-304. DOI
  23. Watson JM, Jenkins EJ, Hamilton P, et al. Influence of caffeine on the frequency and perception of hypoglycemia in free-living patients with type 1 diabetes. Diabetes Care 2000;23:455-9. PubMed
  24. Lloyd T, Johnson-Rollings N, Eggli DF, et al. Bone status among postmenopausal women with different habitual caffeine intakes: a longitudinal investigation. J Am Coll Nutr 2000;19:256-61. PubMed
  25. American Academy of Pediatrics. The transfer of drugs and other chemicals into human milk. Pediatrics 2001;108:776-89. PubMed
  26. Sinclair CJ, Geiger JD. Caffeine use in sports. A pharmacological review. J Sports Med Phys Fitness 2000;40:71-9.
  27. Haller CA, Benowitz NL. Adverse cardiovascular and central nervous system events associated with dietary supplements containing ephedra alkaloids. N Engl J Med 2000;343:1833-8. PubMed
  28. Ali M, Afzal M. A potent inhibitor of thrombin stimulated platelet thromboxane formation from unprocessed tea. Prostaglandins Leukot Med 1987;27:9-13. PubMed
  29. Ardlie NG, Glew G, Schultz BG, Schwartz CJ. Inhibition and reversal of platelet aggregation by methyl xanthines. Thromb Diath Haemorrh 1967;18:670-3. DOI
  30. Ferrini RL, Barrett-Connor E. Caffeine intake and endogenous sex steroid levels in postmenopausal women. The Rancho Bernardo Study. Am J Epidemiol 1996:144:642-4. PubMed
  31. Avisar R, Avisar E, Weinberger D. Effect of coffee consumption on intraocular pressure. Ann Pharmacother 2002;36:992-5.. PubMed
  32. Bell DG, Jacobs I, Ellerington K. Effect of caffeine and ephedrine ingestion on anaerobic exercise performance. Med Sci Sports Exerc 2001;33:1399-403. PubMed
  33. Horner NK, Lampe JW. Potential mechanisms of diet therapy for fibrocystic breast conditions show inadequate evidence of effectiveness. J Am Diet Assoc 2000;100:1368-80. PubMed
  34. Bracken MB, Triche EW, Belanger K, et al. Association of maternal caffeine consumption with decrements in fetal growth. Am J Epidemiol 2003;157:456-66.. PubMed
  35. McGowan JD, Altman RE, Kanto WP Jr. Neonatal withdrawal symptoms after chronic maternal ingestion of caffeine. South Med J 1988;81:1092-4.. PubMed
  36. Massey LK. Is caffeine a risk factor for bone loss in the elderly? Am J Clin Nutr 2001;74:569-70. PubMed
  37. Dreher HM. The effect of caffeine reduction on sleep quality and well-being in persons with HIV. J Psychosom Res 2003;54:191-8.. PubMed
  38. Kockler DR, McCarthy MW, Lawson CL. Seizure activity and unresponsiveness after hydroxycut ingestion. Pharmacotherapy 2001;21:647-51.. PubMed
  39. Schechter MD, Timmons GD. Objectively measured hyperactivity--II. Caffeine and amphetamine effects. J Clin Pharmacol 1985;25:276-80.. PubMed
  40. Nix D, Zelenitsky S, Symonds W, et al. The effect of fluconazole on the pharmacokinetics of caffeine in young and elderly subjects. Clin Pharmacol Ther 1992;51:183. DOI
  41. Infante S, Baeza ML, Calvo M, et al. Anaphylaxis due to caffeine. Allergy 2003;58:681-2. PubMed
  42. Massey LK, Whiting SJ. Caffeine, urinary calcium, calcium metabolism and bone. J Nutr 1993;123:1611-4. PubMed
  43. Nawrot P, Jordan S, Eastwood J, et al. Effects of caffeine on human health. Food Addit Contam 2003;20:1-30. PubMed
  44. May DC, Jarboe CH, VanBakel AB, Williams WM. Effects of cimetidine on caffeine disposition in smokers and nonsmokers. Clin Pharmacol Ther 1982;31:656-61. PubMed
  45. Abernethy DR, Todd EL. Impairment of caffeine clearance by chronic use of low-dose oestrogen-containing oral contraceptives. Eur J Clin Pharmacol 1985;28:425-8. PubMed
  46. Brown NJ, Ryder D, Branch RA. A pharmacodynamic interaction between caffeine and phenylpropanolamine. Clin Pharmacol Ther 1991;50:363-71. PubMed
  47. Sanderink GJ, Bournique B, Stevens J, et al. Involvement of human CYP1A isoenzymes in the metabolism and drug interactions of riluzole in vitro. Pharmacol Exp Ther 1997;282:1465-72. DOI
  48. Wahllander A, Paumgartner G. Effect of ketoconazole and terbinafine on the pharmacokinetics of caffeine in healthy volunteers. Eur J Clin Pharmacol 1989;37:279-83. PubMed
  49. Carrillo JA, Benitez J. Clinically significant pharmacokinetic interactions between dietary caffeine and medications. Clin Pharmacokinet 2000;39:127-53. PubMed
  50. Underwood DA. Which medications should be held before a pharmacologic or exercise stress test? Cleve Clin J Med 2002;69:449-50. PubMed
  51. Aqel RA, Zoghbi GJ, Trimm JR, et al. Effect of caffeine administered intravenously on intracoronary-administered adenosine-induced coronary hemodynamics in patients with coronary artery disease. Am J Cardiol 2004;93:343-6. PubMed
  52. Zheng XM, Williams RC. Serum caffeine levels after 24-hour abstention: clinical implications on dipyridamole (201)Tl myocardial perfusion imaging. J Nucl Med Technol 2002;30:123-7.
  53. Institute of Medicine. Caffeine for the Sustainment of Mental Task Performance: Formulations for Military Operations. Washington, DC: National Academy Press, 2001. Available at: http://books.nap.edu/books/0309082587/html/index.html. DOI
  54. Dews PB, O'Brien CP, Bergman J. Caffeine: behavioral effects of withdrawal and related issues. Food Chem Toxicol 2002;40:1257-61. PubMed
  55. Beach CA, Mays DC, Guiler RC, et al. Inhibition of elimination of caffeine by disulfiram in normal subjects and recovering alcoholics. Clin Pharmacol Ther 1986;39:265-70. PubMed
  56. Juliano LM, Griffiths RR. A critical review of caffeine withdrawal: empirical validation of symptoms and signs, incidence, severity, and associated features. Psychopharmacology (Berl) 2004;176:1-29. PubMed
  57. Winkelmayer WC, Stampfer MJ, Willett WC, Curhan GC. Habitual caffeine intake and the risk of hypertension in women. JAMA 2005;294:2330-5. PubMed
  58. Raaska K, Raitasuo V, Laitila J, Neuvonen PJ. Effect of caffeine-containing versus decaffeinated coffee on serum clozapine concentrations in hospitalised patients. Basic Clin Pharmacol Toxicol 2004;94:13-8. DOI
  59. Forrest WH Jr, Bellville JW, Brown BW Jr. The interaction of caffeine with pentobarbital as a nighttime hypnotic. Anesthesiology 1972;36:37-41. PubMed
  60. Lake CR, Rosenberg DB, Gallant S, et al. Phenylpropanolamine increases plasma caffeine levels. Clin Pharmacol Ther 1990;47:675-85. PubMed
  61. Weng X, Odouli R, Li DK. Maternal caffeine consumption during pregnancy and the risk of miscarriage: a prospective cohort study. Am J Obstet Gynecol 2008;198:279.e1-8. PubMed
  62. Savitz DA, Chan RL, Herring AH, et al. Caffeine and miscarriage risk. Epidemiology 2008;19:55-62. PubMed
  63. Shet, M. S., McPhaul, M., Fisher, C. W., Stallings, N. R., and Estabrook, R. W. Metabolism of the antiandrogenic drug (Flutamide) by human CYP1A2. Drug Metab Dispos. 1997;25(11):1298-1303.
  64. Staib, A. H., Stille, W., Dietlein, G., Shah, P. M., Harder, S., Mieke, S., and Beer, C. Interaction between quinolones and caffeine. Drugs 1987;34 Suppl 1:170-174. PubMed
  65. Stille, W., Harder, S., Mieke, S., Beer, C., Shah, P. M., Frech, K., and Staib, A. H. Decrease of caffeine elimination in man during co-administration of 4-quinolones. J.Antimicrob.Chemother. 1987;20(5):729-734. PubMed
  66. Fuhr, U., Strobl, G., Manaut, F., Anders, E. M., Sorgel, F., Lopez-de-Brinas, E., Chu, D. T., Pernet, A. G., Mahr, G., Sanz, F., and . Quinolone antibacterial agents: relationship between structure and in vitro inhibition of the human cytochrome P450 isof
  67. Kot, M. and Daniel, W. A. Effect of diethyldithiocarbamate (DDC) and ticlopidine on CYP1A2 activity and caffeine metabolism: an in vitro comparative study with human cDNA-expressed CYP1A2 and liver microsomes. Pharmacol Rep. 2009;61(6):1216-1220. PubMed
  68. Gasior, M., Borowicz, K., Buszewicz, G., Kleinrok, Z., and Czuczwar, S. J. Anticonvulsant activity of phenobarbital and valproate against maximal electroshock in mice during chronic treatment with caffeine and caffeine discontinuation. Epilepsia 1996;37(3 PubMed
  69. Jankiewicz, K., Chroscinska-Krawczyk, M., Blaszczyk, B., and Czuczwar, S. J. [Caffeine and antiepileptic drugs: experimental and clinical data]. Przegl.Lek. 2007;64(11):965-967.
  70. Luszczki, J. J., Zuchora, M., Sawicka, K. M., Kozinska, J., and Czuczwar, S. J. Acute exposure to caffeine decreases the anticonvulsant action of ethosuximide, but not that of clonazepam, phenobarbital and valproate against pentetrazole-induced seizures i
  71. Chroscinska-Krawczyk, M., Jargiello-Baszak, M., Walek, M., Tylus, B., and Czuczwar, S. J. Caffeine and the anticonvulsant potency of antiepileptic drugs: experimental and clinical data. Pharmacol.Rep. 2011;63(1):12-18. PubMed
  72. Vaz, J., Kulkarni, C., David, J., and Joseph, T. Influence of caffeine on pharmacokinetic profile of sodium valproate and carbamazepine in normal human volunteers. Indian J.Exp.Biol. 1998;36(1):112-114.
  73. Gasior, M., Swiader, M., Przybylko, M., Borowicz, K., Turski, W. A., Kleinrok, Z., and Czuczwar, S. J. Felbamate demonstrates low propensity for interaction with methylxanthines and Ca2+ channel modulators against experimental seizures in mice. Eur.J Phar PubMed
  74. Balogh, A., Klinger, G., Henschel, L., Borner, A., Vollanth, R., and Kuhnz, W. Influence of ethinylestradiol-containing combination oral contraceptives with gestodene or levonorgestrel on caffeine elimination. Eur.J.Clin.Pharmacol. 1995;48(2):161-166. PubMed
  75. Mohiuddin, M., Azam, A. T., Amran, M. S., and Hossain, M. A. In vive effects of gliclazide and metformin on the plasma concentration of caffeine in healthy rats. Pak.J Biol Sci 5-1-2009;12(9):734-737.
  76. Mays, D. C., Camisa, C., Cheney, P., Pacula, C. M., Nawoot, S., and Gerber, N. Methoxsalen is a potent inhibitor of the metabolism of caffeine in humans. Clin.Pharmacol.Ther. 1987;42(6):621-626. PubMed
  77. Wojcikowski, J. and Daniel, W. A. Perazine at therapeutic drug concentrations inhibits human cytochrome P450 isoenzyme 1A2 (CYP1A2) and caffeine metabolism--an in vitro study. Pharmacol Rep. 2009;61(5):851-858. PubMed
  78. Daniel, W. A., Syrek, M., Rylko, Z., and Kot, M. Effects of phenothiazine neuroleptics on the rate of caffeine demethylation and hydroxylation in the rat liver. Pol.J Pharmacol 2001;53(6):615-621.
  79. Norager, C. B., Jensen, M. B., Weimann, A., and Madsen, M. R. Metabolic effects of caffeine ingestion and physical work in 75-year old citizens. A randomized, double-blind, placebo-controlled, cross-over study. Clin Endocrinol (Oxf) 2006;65(2):223-228. PubMed
  80. Bailey, D. N., Weibert, R. T., Naylor, A. J., and Shaw, R. F. A study of salicylate and caffeine excretion in the breast milk of two nursing mothers. J.Anal.Toxicol. 1982;6(2):64-68. PubMed
  81. Griffiths, R. R. and Chausmer, A. L. Caffeine as a model drug of dependence: recent developments in understanding caffeine withdrawal, the caffeine dependence syndrome, and caffeine negative reinforcement. Nihon Shinkei Seishin Yakurigaku Zasshi 2000;20(
  82. Karacan, I., Thornby, J. I., Anch, M., Booth, G. H., Williams, R. L., and Salis, P. J. Dose-related sleep disturbances induced by coffee and caffeine. Clin Pharmacol Ther 1976;20(6):682-689. PubMed
  83. Quirce, G. S., Freire, P., Fernandez, R. M., Davila, I., and Losada, E. Urticaria from caffeine. J.Allergy Clin Immunol. 1991;88(4):680-681. PubMed
  84. Hughes, J. R., Higgins, S. T., Bickel, W. K., Hunt, W. K., Fenwick, J. W., Gulliver, S. B., and Mireault, G. C. Caffeine self-administration, withdrawal, and adverse effects among coffee drinkers. Arch.Gen.Psychiatry 1991;48(7):611-617. PubMed
  85. Adams, B. A. and Brubaker, R. F. Caffeine has no clinically significant effect on aqueous humor flow in the normal human eye. Ophthalmology 1990;97(8):1030-1031. PubMed
  86. Davis, R. H. Does caffeine ingestion affect intraocular pressure?. Ophthalmology 1989;96(11):1680-1681. PubMed
  87. Higginbotham, E. J., Kilimanjaro, H. A., Wilensky, J. T., Batenhorst, R. L., and Hermann, D. The effect of caffeine on intraocular pressure in glaucoma patients. Ophthalmology 1989;96(5):624-626.
  88. Wrenn, K. D. and Oschner, I. Rhabdomyolysis induced by a caffeine overdose. Ann.Emerg.Med. 1989;18(1):94-97. PubMed
  89. Pola, J., Subiza, J., Armentia, A., Zapata, C., Hinojosa, M., Losada, E., and Valdivieso, R. Urticaria caused by caffeine. Ann.Allergy 1988;60(3):207-208.
  90. Lane, J. D. and Williams, R. B., Jr. Cardiovascular effects of caffeine and stress in regular coffee drinkers. Psychophysiology 1987;24(2):157-164. PubMed
  91. Shirlow, M. J. and Mathers, C. D. A study of caffeine consumption and symptoms; indigestion, palpitations, tremor, headache and insomnia. Int.J.Epidemiol. 1985;14(2):239-248. PubMed
  92. Stillner, V., Popkin, M. K., and Pierce, C. M. Caffeine-induced delirium during prolonged competitive stress. Am.J.Psychiatry 1978;135(7):855-856. PubMed
  93. Levy, M. and Zylber-Katz, E. Caffeine metabolism and coffee-attributed sleep disturbances. Clin Pharmacol Ther 1983;33(6):770-775. PubMed
  94. Brown, S. L., Salive, M. E., Pahor, M., Foley, D. J., Corti, M. C., Langlois, J. A., Wallace, R. B., and Harris, T. B. Occult caffeine as a source of sleep problems in an older population. J.Am.Geriatr.Soc. 1995;43(8):860-864. PubMed
  95. Sung, B. H., Whitsett, T. L., Lovallo, W. R., al'Absi, M., Pincomb, G. A., and Wilson, M. F. Prolonged increase in blood pressure by a single oral dose of caffeine in mildly hypertensive men. Am.J Hypertens. 1994;7(8):755-758. PubMed
  96. Caballero, T., Garcia-Ara, C., Pascual, C., Diaz-Pena, J. M., and Ojeda, A. Urticaria induced by caffeine. J.Investig.Allergol.Clin Immunol. 1993;3(3):160-162.
  97. Smits, P., Temme, L., and Thien, T. The cardiovascular interaction between caffeine and nicotine in humans. Clin Pharmacol Ther 1993;54(2):194-204. PubMed
  98. Garrett, B. E. and Griffiths, R. R. Physical dependence increases the relative reinforcing effects of caffeine versus placebo. Psychopharmacology (Berl) 1998;139(3):195-202. PubMed
  99. Lane, J. D. and Phillips-Bute, B. G. Caffeine deprivation affects vigilance performance and mood. Physiol Behav. 1998;65(1):171-175. PubMed
  100. Boekema, P. J., Samsom, M., van Berge Henegouwen, G. P., and Smout, A. J. Coffee and gastrointestinal function: facts and fiction. A review. Scand J Gastroenterol.Suppl 1999;230:35-39. PubMed
  101. Terry, P., Lagergren, J., Wolk, A., and Nyren, O. Reflux-inducing dietary factors and risk of adenocarcinoma of the esophagus and gastric cardia. Nutr Cancer 2000;38(2):186-191.
  102. Pollak, C. P. and Bright, D. Caffeine consumption and weekly sleep patterns in US seventh-, eighth-, and ninth-graders. Pediatrics 2003;111(1):42-46. PubMed
  103. DiBaise, J. K. A randomized, double-blind comparison of two different coffee-roasting processes on development of heartburn and dyspepsia in coffee-sensitive individuals. Dig.Dis.Sci 2003;48(4):652-656. PubMed
  104. Wang, J. H., Luo, J. Y., Dong, L., Gong, J., and Tong, M. Epidemiology of gastroesophageal reflux disease: a general population-based study in Xi'an of Northwest China. World J Gastroenterol. 6-1-2004;10(11):1647-1651. PubMed
  105. Naliboff, B. D., Mayer, M., Fass, R., Fitzgerald, L. Z., Chang, L., Bolus, R., and Mayer, E. A. The effect of life stress on symptoms of heartburn. Psychosom.Med 2004;66(3):426-434. PubMed
  106. Massey, L. K. and Sutton, R. A. Acute caffeine effects on urine composition and calcium kidney stone risk in calcium stone formers. J.Urol. 2004;172(2):555-558. PubMed
  107. Tavani, A. and La, Vecchia C. Coffee, decaffeinated coffee, tea and cancer of the colon and rectum: a review of epidemiological studies, 1990-2003. Cancer Causes Control 2004;15(8):743-757. PubMed
  108. Noordzij, M., Uiterwaal, C. S., Arends, L. R., Kok, F. J., Grobbee, D. E., and Geleijnse, J. M. Blood pressure response to chronic intake of coffee and caffeine: a meta-analysis of randomized controlled trials. J Hypertens. 2005;23(5):921-928. PubMed
  109. Chandrasekaran, S., Rochtchina, E., and Mitchell, P. Effects of caffeine on intraocular pressure: the Blue Mountains Eye Study. J Glaucoma. 2005;14(6):504-507. PubMed
  110. Morgan, J. C. and Sethi, K. D. Drug-induced tremors. Lancet Neurol. 2005;4(12):866-876. PubMed
  111. Doan, B. K., Hickey, P. A., Lieberman, H. R., and Fischer, J. R. Caffeinated tube food effect on pilot performance during a 9-hour, simulated nighttime U-2 mission. Aviat.Space Environ Med 2006;77(10):1034-1040.
  112. Whalen, D. J., Silk, J. S., Semel, M., Forbes, E. E., Ryan, N. D., Axelson, D. A., Birmaher, B., and Dahl, R. E. Caffeine consumption, sleep, and affect in the natural environments of depressed youth and healthy controls. J Pediatr.Psychol. 2008;33(4):35 PubMed
  113. MacKenzie, T., Comi, R., Sluss, P., Keisari, R., Manwar, S., Kim, J., Larson, R., and Baron, J. A. Metabolic and hormonal effects of caffeine: randomized, double-blind, placebo-controlled crossover trial. Metabolism 2007;56(12):1694-1698. PubMed
  114. Mort, J. R. and Kruse, H. R. Timing of blood pressure measurement related to caffeine consumption. Ann Pharmacother. 2008;42(1):105-110.
  115. Ganmaa, D., Willett, W. C., Li, T. Y., Feskanich, D., van Dam, R. M., Lopez-Garcia, E., Hunter, D. J., and Holmes, M. D. Coffee, tea, caffeine and risk of breast cancer: a 22-year follow-up. Int J Cancer 5-1-2008;122(9):2071-2076. PubMed
  116. Killgore, W. D., Rupp, T. L., Grugle, N. L., Reichardt, R. M., Lipizzi, E. L., and Balkin, T. J. Effects of dextroamphetamine, caffeine and modafinil on psychomotor vigilance test performance after 44 h of continuous wakefulness. J Sleep Res 2008;17(3):3 PubMed
  117. Ozsungur, S., Brenner, D., and El-Sohemy, A. Fourteen well-described caffeine withdrawal symptoms factor into three clusters. Psychopharmacology (Berl) 2009;201(4):541-548. PubMed
  118. Ishitani, K., Lin, J., Manson, J. E., Buring, J. E., and Zhang, S. M. Caffeine consumption and the risk of breast cancer in a large prospective cohort of women. Arch Intern Med 10-13-2008;168(18):2022-2031. PubMed
  119. Tunnicliffe, J. M., Erdman, K. A., Reimer, R. A., Lun, V., and Shearer, J. Consumption of dietary caffeine and coffee in physically active populations: physiological interactions. Appl Physiol Nutr Metab 2008;33(6):1301-1310. PubMed
  120. Sin, C. W., Ho, J. S., and Chung, J. W. Systematic review on the effectiveness of caffeine abstinence on the quality of sleep. J Clin Nurs. 2009;18(1):13-21. PubMed
  121. Lopez-Garcia, E., Rodriguez-Artalejo, F., Rexrode, K. M., Logroscino, G., Hu, F. B., and van Dam, R. M. Coffee consumption and risk of stroke in women. Circulation 3-3-2009;119(8):1116-1123. PubMed
  122. Zhang, W., Lopez-Garcia, E., Li, T. Y., Hu, F. B., and van Dam, R. M. Coffee consumption and risk of cardiovascular diseases and all-cause mortality among men with type 2 diabetes. Diabetes Care 2009;32(6):1043-1045. PubMed
  123. Killgore, W. D., Kahn-Greene, E. T., Grugle, N. L., Killgore, D. B., and Balkin, T. J. Sustaining executive functions during sleep deprivation: A comparison of caffeine, dextroamphetamine, and modafinil. Sleep 2-1-2009;32(2):205-216. PubMed
  124. Natale, F., Cirillo, C., Di Marco, G. M., di Vetta, L. S., Aronne, L., Siciliano, A., Mocerino, R., Tedesco, M. A., Golino, P., and Calabro, R. When chewing gum is more than just a bad habit. Lancet 5-30-2009;373(9678):1918. PubMed
  125. Calamaro, C. J., Mason, T. B., and Ratcliffe, S. J. Adolescents living the 24/7 lifestyle: effects of caffeine and technology on sleep duration and daytime functioning. Pediatrics 2009;123(6):e1005-e1010. PubMed
  126. Koran, L. M., Aboujaoude, E., and Gamel, N. N. Double-blind study of dextroamphetamine versus caffeine augmentation for treatment-resistant obsessive-compulsive disorder. J Clin Psychiatry 2009;70(11):1530-1535. PubMed
  127. Luebbe, A. M. and Bell, D. J. Mountain Dew or mountain don't?: a pilot investigation of caffeine use parameters and relations to depression and anxiety symptoms in 5th- and 10th-grade students. J Sch Health 2009;79(8):380-387.
  128. Skouroliakou, M., Bacopoulou, F., and Markantonis, S. L. Caffeine versus theophylline for apnea of prematurity: a randomised controlled trial. J Paediatr.Child Health 2009;45(10):587-592. PubMed
  129. Urade, Y. [Molecular mechanisms of insomnia]. Nippon Rinsho 2009;67(8):1489-1493.
  130. Montandon, G., Horner, R. L., Kinkead, R., and Bairam, A. Caffeine in the neonatal period induces long-lasting changes in sleep and breathing in adult rats. J Physiol 11-15-2009;587(Pt 22):5493-5507. PubMed
  131. Addicott, M. A. and Laurienti, P. J. A comparison of the effects of caffeine following abstinence and normal caffeine use. Psychopharmacology (Berl) 2009;207(3):423-431. PubMed
  132. Hashim, H. and Al, Mousa R. Management of fluid intake in patients with overactive bladder. Curr.Urol.Rep. 2009;10(6):428-433. PubMed
  133. Moisey, L. L., Robinson, L. E., and Graham, T. E. Consumption of caffeinated coffee and a high carbohydrate meal affects postprandial metabolism of a subsequent oral glucose tolerance test in young, healthy males. Br.J Nutr. 2010;103(6):833-841. PubMed
  134. Chroscinska-Krawczyk, M., Ratnaraj, N., Patsalos, P. N., and Czuczwar, S. J. Effect of caffeine on the anticonvulsant effects of oxcarbazepine, lamotrigine and tiagabine in a mouse model of generalized tonic-clonic seizures. Pharmacol Rep. 2009;61(5):819 PubMed
  135. Attwood, A., Terry, P., and Higgs, S. Conditioned effects of caffeine on performance in humans. Physiol Behav 3-3-2010;99(3):286-293. PubMed
  136. Skinner, T. L., Jenkins, D. G., Coombes, J. S., Taaffe, D. R., and Leveritt, M. D. Dose response of caffeine on 2000-m rowing performance. Med Sci Sports Exerc. 2010;42(3):571-576. PubMed
  137. Holick, C. N., Smith, S. G., Giovannucci, E., and Michaud, D. S. Coffee, tea, caffeine intake, and risk of adult glioma in three prospective cohort studies. Cancer Epidemiol.Biomarkers Prev 2010;19(1):39-47. PubMed
  138. Simmonds, M. J., Minahan, C. L., and Sabapathy, S. Caffeine improves supramaximal cycling but not the rate of anaerobic energy release. Eur.J Appl Physiol 2010;109(2):287-295. PubMed
  139. Buscemi, S., Verga, S., Batsis, J. A., Donatelli, M., Tranchina, M. R., Belmonte, S., Mattina, A., Re, A., and Cerasola, G. Acute effects of coffee on endothelial function in healthy subjects. Eur.J Clin Nutr. 2010;64(5):483-489. PubMed
  140. Rigato, I., Blarasin, L., and Kette, F. Severe hypokalemia in 2 young bicycle riders due to massive caffeine intake. Clin J Sport Med. 2010;20(2):128-130. PubMed
  141. Greenwood, D. C., Alwan, N., Boylan, S., Cade, J. E., Charvill, J., Chipps, K. C., Cooke, M. S., Dolby, V. A., Hay, A. W., Kassam, S., Kirk, S. F., Konje, J. C., Potdar, N., Shires, S., Simpson, N., Taub, N., Thomas, J. D., Walker, J., White, K. L., and
  142. Mevcha, A., Gulur, D. M., and Gillatt, D. Diagnosing urological disorders in ageing men. Practitioner 2010;254(1726):25-9, 2.
  143. Brick, C. A., Seely, D. L., and Palermo, T. M. Association between sleep hygiene and sleep quality in medical students. Behav Sleep Med 2010;8(2):113-121. PubMed
  144. Digdon, N. L. Circadian preference and college students' beliefs about sleep education. Chronobiol.Int 2010;27(2):297-317. PubMed
  145. Boos, C. J., White, S. H., Bland, S. A., and McAllister, P. D. Dietary supplements and military operations: caution is advised. J R.Army Med Corps 2010;156(1):41-43. PubMed
  146. Casiglia, E., Bongiovi, S., Paleari, C. D., Petucco, S., Boni, M., Colangeli, G., Penzo, M., and Pessina, A. C. Haemodynamic effects of coffee and caffeine in normal volunteers: a placebo-controlled clinical study. J.Intern.Med. 1991;229(6):501-504. PubMed
  147. Aguggia, M. and Saracco, M. G. Pathophysiology of migraine chronification. Neurol.Sci 2010;31 Suppl 1:S15-S17. PubMed
  148. Torelli, P. and Manzoni, G. C. Fasting headache. Curr Pain Headache Rep. 2010;14(4):284-291.
  149. Farag, N. H., Whitsett, T. L., McKey, B. S., Wilson, M. F., Vincent, A. S., Everson-Rose, S. A., and Lovallo, W. R. Caffeine and blood pressure response: sex, age, and hormonal status. J Womens Health (Larchmt.) 2010;19(6):1171-1176. PubMed
  150. Ernest, D., Chia, M., and Corallo, C. E. Profound hypokalaemia due to Nurofen Plus and Red Bull misuse. Crit Care Resusc. 2010;12(2):109-110. DOI
  151. Suen, L. K., Tam, W. W., and Hon, K. L. Association of sleep hygiene-related factors and sleep quality among university students in Hong Kong. Hong.Kong.Med.J 2010;16(3):180-185.
  152. Stafford, L. D., Wright, C., and Yeomans, M. R. The drink remains the same: implicit positive associations in high but not moderate or non-caffeine users. Psychol.Addict.Behav. 2010;24(2):274-281. PubMed
  153. Conen, D., Chiuve, S. E., Everett, B. M., Zhang, S. M., Buring, J. E., and Albert, C. M. Caffeine consumption and incident atrial fibrillation in women. Am J Clin Nutr 2010;92(3):509-514. PubMed
  154. Freire, R. C., Perna, G., and Nardi, A. E. Panic disorder respiratory subtype: psychopathology, laboratory challenge tests, and response to treatment. Harv.Rev.Psychiatry 2010;18(4):220-229. PubMed
  155. Reis, J. P., Loria, C. M., Steffen, L. M., Zhou, X., van, Horn L., Siscovick, D. S., Jacobs, D. R., Jr., and Carr, J. J. Coffee, decaffeinated coffee, caffeine, and tea consumption in young adulthood and atherosclerosis later in life: the CARDIA study. A PubMed
  156. Clausen, T. Hormonal and pharmacological modification of plasma potassium homeostasis. Fundam.Clin Pharmacol 2010;24(5):595-605. PubMed
  157. Kujawa-Hadrys, M., Tosik, D., and Bartel, H. Changes in thickness of each layer of developing chicken cornea after administration of caffeine. Folia Histochem.Cytobiol. 2010;48(2):273-277. PubMed
  158. Boggs, D. A., Palmer, J. R., Stampfer, M. J., Spiegelman, D., Adams-Campbell, L. L., and Rosenberg, L. Tea and coffee intake in relation to risk of breast cancer in the Black Women's Health Study. Cancer Causes Control 2010;21(11):1941-1948. PubMed
  159. Li, S., Zhu, S., Jin, X., Yan, C., Wu, S., Jiang, F., and Shen, X. Risk factors associated with short sleep duration among Chinese school-aged children. Sleep Med. 2010;11(9):907-916. PubMed
  160. Gronroos, N. N. and Alonso, A. Diet and risk of atrial fibrillation - epidemiologic and clinical evidence -. Circ.J 2010;74(10):2029-2038. PubMed
  161. Knight, J. M., Avery, E. F., Janssen, I., and Powell, L. H. Cortisol and depressive symptoms in a population-based cohort of midlife women. Psychosom.Med. 2010;72(9):855-861. PubMed
  162. Porkka-Heiskanen, T. Methylxanthines and sleep. Handb.Exp.Pharmacol 2011;(200):331-348. PubMed
  163. Mostofsky, E., Schlaug, G., Mukamal, K. J., Rosamond, W. D., and Mittleman, M. A. Coffee and acute ischemic stroke onset: the Stroke Onset Study. Neurology 11-2-2010;75(18):1583-1588. PubMed
  164. Orozco-Gregorio, H., Mota-Rojas, D., Bonilla-Jaime, H., Trujillo-Ortega, M. E., Becerril-Herrera, M., Hernandez-Gonzalez, R., and Villanueva-Garcia, D. Effects of administration of caffeine on metabolic variables in neonatal pigs with peripartum asphyxia PubMed
  165. Li, G. Z., Zhang, N., Du, P., Yang, Y., Wu, S. L., Xiao, Y. X., Jin, R., Liu, L., Shen, H., and Dai, Y. Risk factors for interstitial cystitis/painful bladder syndrome in patients with lower urinary tract symptoms: a Chinese multi-center study. Chin Med
  166. Duvnjak-Zaknich, D. M., Dawson, B. T., Wallman, K. E., and Henry, G. Effect of caffeine on reactive agility time when fresh and fatigued. Med.Sci.Sports Exerc. 2011;43(8):1523-1530. PubMed
  167. Astorino, T. A., Martin, B. J., Schachtsiek, L., Wong, K., and Ng, K. Minimal effect of acute caffeine ingestion on intense resistance training performance. J Strength.Cond.Res 2011;25(6):1752-1758. PubMed
  168. Kivity, S., Ben Aharon, Y., Man, A., and Topilsky, M. The effect of caffeine on exercise-induced bronchoconstriction. Chest 1990;97(5):1083-1085. PubMed
  169. Lubin, F. and Ron, E. Consumption of methylxanthine-containing beverages and the risk of breast cancer. Cancer Lett. 1990;53(2-3):81-90. PubMed
  170. Smits, P., Lenders, J. W., and Thien, T. Caffeine and theophylline attenuate adenosine-induced vasodilation in humans. Clin.Pharmacol.Ther. 1990;48(4):410-418. PubMed
  171. Rossignol, A. M. and Bonnlander, H. Caffeine-containing beverages, total fluid consumption, and premenstrual syndrome. Am.J.Public Health 1990;80(9):1106-1110. PubMed
  172. Birkett, N. J. and Logan, A. G. Caffeine-containing beverages and the prevalence of hypertension. J Hypertens.Suppl 1988;6(4):S620-S622. PubMed
  173. Fraumeni, J. F., Jr., Scotto, J., and Dunham, L. J. Coffee-drinking and bladder cancer. Lancet 11-27-1971;2(7735):1204. PubMed
  174. Greden, J. F. Anxiety or caffeinism: a diagnostic dilemma. Am J Psychiatry 1974;131(10):1089-1092. PubMed
  175. Whitsett, T. L., Manion, C. V., and Christensen, H. D. Cardiovascular effects of coffee and caffeine. Am.J.Cardiol. 3-15-1984;53(7):918-922. PubMed
  176. Firestone, P., Poitras-Wright, H., and Douglas, V. The effects of caffeine on hyperactive children. J.Learn.Disabil. 1978;11(3):133-141. PubMed
  177. Thomas, F. B., Steinbaugh, J. T., Fromkes, J. J., Mekhjian, H. S., and Caldwell, J. H. Inhibitory effect of coffee on lower esophageal sphincter pressure. Gastroenterology 1980;79(6):1262-1266. DOI
  178. Linn, S., Schoenbaum, S. C., Monson, R. R., Rosner, B., Stubblefield, P. G., and Ryan, K. J. No association between coffee consumption and adverse outcomes of pregnancy. N.Engl.J Med 1-21-1982;306(3):141-145. PubMed
  179. Cohen, S. Pathogenesis of coffee-induced gastrointestinal symptoms. N.Engl.J Med 7-17-1980;303(3):122-124. PubMed
  180. Feldman, M. and Barnett, C. Relationships between the acidity and osmolality of popular beverages and reported postprandial heartburn. Gastroenterology 1995;108(1):125-131. PubMed
  181. Quinlan, P., Lane, J., and Aspinall, L. Effects of hot tea, coffee and water ingestion on physiological responses and mood: the role of caffeine, water and beverage type. Psychopharmacology (Berl) 1997;134(2):164-173. PubMed
  182. Youngstedt, S. D., O'Connor, P. J., Crabbe, J. B., and Dishman, R. K. Acute exercise reduces caffeine-induced anxiogenesis. Med.Sci Sports Exerc. 1998;30(5):740-745. PubMed
  183. Kaminsky, L. A., Martin, C. A., and Whaley, M. H. Caffeine consumption habits do not influence the exercise blood pressure response following caffeine ingestion. J.Sports Med.Phys.Fitness 1998;38(1):53-58.
  184. McManamy, M. C. and Schube, P. G. Caffeine intoxication: report of a case the symptoms of which amounted to a psychosis. New England Journal of Medicine 1936;215:616-620. DOI
  185. Richter, J. E., Katz, P. O., and Waring, J. P. Gastroesophageal Reflux Disease. IFFGD 2000;
  186. Hsu, C., Harden, R. N., and Houle, T. Nicotine and caffeine intake in complex regional pain syndrome. Journal of Back and Musculoskeletal Rehabilitation 2002;16(1):33-38. PubMed
  187. Luebbe, A. M. Child and Adolescent Anxiety Sensitivity, Perceived Subjective Effects of Caffeine and Caffeine Consumption. J Caffeine Res 2011;1(4):213-218. DOI
  188. Li-Neng, Y., Greenstadt, L., and Shapiro, D. Effects of caffeine on blood pressure:A cross-cultural comparison. Psychophysiology 1983;20
  189. Fotherby, M. D., Ghandi, C., Haigh, R. A., Macdonald, T. A., and Potter, J. F. Sustained caffeine use has no pressor effect in the elderly. Cardiology in the Elderly 1994;2(6):499-503.
  190. Basurto Ona X, Uriona Tuma SM, Martínez García L, Solà I, Bonfill Cosp X. Drug therapy for preventing post-dural puncture headache. Cochrane Database Syst Rev. 2013 28;2:CD001792. doi: 10.1002/14651858.CD001792.pub3. Review. PubMed
  191. Beaudoin MS, Allen B, Mazzetti G, Sullivan PJ, Graham TE. Caffeine ingestion impairs insulin sensitivity in a dose-dependent manner in both men and women. Appl Physiol Nutr Metab. 2013;38(2):140-7. doi: 10.1139/apnm-2012-0201. Epub 2012 9. PubMed
  192. Caldeira D, Martins C, Alves LB, Pereira H, Ferreira JJ, Costa J. Caffeine does not increase the risk of atrial fibrillation: a systematic review and meta-analysis of observational studies. Heart. 2013;99(19):1383-9. doi: 10.1136/heartjnl-2013-303950. Re PubMed
  193. Chen L, Bell EM, Browne ML, Druschel CM, Romitti PA, Schmidt RJ, Burns TL, Moslehi R, Olney RS; National Birth Defects Prevention Study. Maternal caffeine consumption and risk of congenital limb deficiencies. Birth Defects Res A Clin Mol Teratol. 2012 De PubMed
  194. Chen LW, Wu Y, Neelakantan N, Chong MF, Pan A, van Dam RM. Maternal caffeine intake during pregnancy is associated with risk of low birth weight: a systematic review and dose-response meta-analysis. BMC Med. 2014 19;12:174. doi: 10.1186/s12916-014-0174-6 PubMed
  195. Cheng M, Hu Z, Lu X, Huang J, Gu D. Caffeine intake and atrial fibrillation incidence: dose response meta-analysis of prospective cohort studies. Can J Cardiol. 2014 Apr;30(4):448-54. doi: 10.1016/j.cjca.2013.12.026. Epub 2014 2. Review. PubMed
  196. Chiaffarino F, Bravi F, Cipriani S, Parazzini F, Ricci E, Viganò P, La Vecchia C. Coffee and caffeine intake and risk of endometriosis: a meta-analysis. Eur J Nutr. 2014 Oct;53(7):1573-9. doi: 10.1007/s00394-014-0662-7. Epub 2014 31. PubMed
  197. Greenwood DC, Thatcher NJ, Ye J, Garrard L, Keogh G, King LG, Cade JE. Caffeine intake during pregnancy and adverse birth outcomes: a systematic review and dose-response meta-analysis. Eur J Epidemiol. 2014;29(10):725-34. doi: 10.1007/s10654-014-9944-x. PubMed
  198. Jiang W, Wu Y, Jiang X. Coffee and caffeine intake and breast cancer risk: an updated dose-response meta-analysis of 37 published studies. Gynecol Oncol. 2013 Jun;129(3):620-9. doi: 10.1016/j.ygyno.2013.03.014. Epub 2013 25. Review. PubMed
  199. Lee SM, Choi NK, Lee BC, Cho KH, Yoon BW, Park BJ. Caffeine-containing medicines increase the risk of hemorrhagic stroke. Stroke. 2013 Aug;44(8):2139-43. doi: 10.1161/STROKEAHA.111.674077. Epub 2013 6. PubMed
  200. Sanikini H, Dik VK, Siersema PD, Bhoo-Pathy N, Uiterwaal CS, Peeters PH, González CA, Zamora-Ros R, Overvad K, Tjønneland A, Roswall N, Boutron-Ruault MC, Fagherazzi G, Racine A, Kühn T, Katzke V, Boeing H, Trichopoulou A, Trichopoulos D, Lagiou P, Palli
  201. Simonin C, Duru C, Salleron J, Hincker P, Charles P, Delval A, Youssov K, Burnouf S, Azulay JP, Verny C, Scherer C, Tranchant C, Goizet C, Debruxelles S, Defebvre L, Sablonnière B, Romon-Rousseaux M, Buée L, Destée A, Godefroy O, Dürr A, Landwehrmeyer B;
  202. Szpak A, Allen D. A case of acute suicidality following excessive caffeine intake. J Psychopharmacol. 2012 Nov;26(11):1502-10. doi: 10.1177/0269881112442788. Epub 2012 2. PubMed
  203. van der Hoeven N, Visser I, Schene A, van den Born BJ. Severe hypertension related to caffeinated coffee and tranylcypromine: a case report. Ann Intern Med. 2014 May 6;160(9):657-8. doi: 10.7326/L14-5009-8. No abstract available. PubMed
  204. Dixit S, Stein PK, Dewland TA, Dukes JW, Vittinghoff E, Heckbert SR, Marcus GM. Consumption of Caffeinated Products and Cardiac Ectopy. J Am Heart Assoc. 2016 26;5(1). pii: e002503. doi: 10.1161/JAHA.115.002503. PubMed
  205. Sheppard SG. A preliminary investigation of ibogaine: case reports and recommendations for further study. J Subst Abuse Treat. 1994 Jul-Aug;11(4):379-85. PubMed
  206. Zuchinali P, Riberio PA, Pimentel M, da Rosa PR, Zimerman LI, Rohde LE. Effect of caffeine on ventricular arrhythmia: a systematic review and meta-analysis of experimental and clinical studies. Europace 2016 Feb;18(2):257-66. PubMed
  207. Rhee J, Kim R, Kim Y, et al. Maternal caffeine consumption during pregnancy and risk of low birth weight: a dose-response meta-analysis of observational studies. PLoS One. 2015 Jul 20;10(7):e0132334. PubMed
  208. Zuchinali P, Souza GC, Pimentel M, et al. Short-term effects of high-dose caffeine on cardiac arrhythmias in patients with heart failure: a randomized clinical trial. JAMA Intern Med. 2016 Dec 1;176(12):1752-59. PubMed
  209. Lystrup RM, Leggit JC. Caffeine toxicity due to supplement use in caffeine - naïve individual: a cautionary tale. Mil Med. 2015 Aug;180(8):e936-40. PubMed
  210. Magdalan J, Zawadzki M, Skowronek R, et al. Nonfatal and fata intoxications with pure caffeine - report of three different cases. Forensic Sci Med Pathol. 2017 Sep;13(3):355-58.
  211. Trexler ET, Smith-Ryan AE, Roelofs EJ, Hirsch KR, Persky AM, Mock AG. Effects of coffee and caffeine anhydrous intake during creatine loading. J Strength Cond Res. 2016 May;30(5):1438-46. PubMed
  212. Lagier D, Nee L, Guieu R, et al. Peri-operative oral caffeine does not prevent postoperative atrial fibrillation after heart valve surgery with cardiopulmonary bypass: a randomized controlled clinical trial. Eur J Anaesthesiol. 2018 Apr 26. [Epub ahead of DOI
  213. Voskoboinik A, Kalman JM, Kistler PM. Caffeine and arrhythmias: time to grind the data. JACC: Clin Electrophysiol. 2018;4(4):425-32. PubMed
  214. Wang HR, Woo YS, Bahk WM. Caffeine-induced psychiatric manifestations: a review. Int Clin Psychopharmacol. 2015 Jul;30(4):179-82. PubMed
  215. Wikoff D, Welsh BT, Henderson R, et al. Systematic review of the potential adverse effects of caffeine consumption in healthy adults, pregnant women, adolescents, and children. Food Chem Toxicol 2017;109:585-648. PubMed
  216. Vliegenthart R, Miedema M, Hutten GJ, van Kaam AH, Onland W. High versus standard dose caffeine for apnoea: a systematic review. Arch Dis Child Fetal Neonatal Ed 2018;103(6):F523-9. doi: 10.1136/archdischild-2017-313556. PubMed
  217. Modzelewska D, Bellocco R, Elfvin A, et al. Caffeine exposure during pregnancy, small for gestational age birth and neonatal outcome - results from the Norwegian Mother and Child Cohort Study. BMC Pregnancy Childbirth. 2019;19(1):80. PubMed
  218. Shen JG, Brooks MB, Cincotta J, Manjourides JD. Establishing a relationship between the effect of caffeine and duration of endurance athletic time trial events: A systematic review and meta-analysis. J Sci Med Sport. 2019;22(2):232-238. PubMed
  219. Berglundh S, Vollrath M, Brantsæter AL, et al. Maternal caffeine intake during pregnancy and child neurodevelopment up to eight years of age-Results from the Norwegian Mother, Father and Child Cohort Study. Eur J Nutr. 2020. PubMed
  220. Jin F, Qiao C. Association of maternal caffeine intake during pregnancy with low birth weight, childhood overweight, and obesity: a meta-analysis of cohort studies. Int J Obes (Lond). 2020. PubMed
  221. Krittanawong C, Tunhasiriwet A, Wang Z, et al. Is caffeine or coffee consumption a risk for new-onset atrial fibrillation? A systematic review and meta-analysis. Eur J Prev Cardiol. 2020:2047487320908385. PubMed
  222. Zhang H, Lee ZX, Qiu A. Caffeine intake and cognitive functions in children. Psychopharmacology (Berl). 2020;237(10):3109-3116. PubMed
  223. Stojanovic E, Scanlan AT, Milanovic Z, Fox JL, Stankovic R, Dalbo VJ. Acute caffeine supplementation improves jumping, sprinting, and change-of-direction performance in basketball players when ingested in the morning but not evening. Eur J Sport Sci. 2021 PubMed
  224. Zheng KH, Zhu K, Wactawski-Wende J, et al. Caffeine intake from coffee and tea and invasive breast cancer incidence among postmenopausal women in the Women's Health Initiative. Int J Cancer 2021;149(12):2032-2044. PubMed
  225. Wang S, Li X, Yang Y, et al. Does coffee, tea and caffeine consumption reduce the risk of incident breast cancer? A systematic review and network meta-analysis. Public Health Nutr 2021;24(18):6377-6389. PubMed
  226. Alshabi AM, Alkahtani SA, Shaikh IA, Habeeb MS. Caffeine modulates pharmacokinetic and pharmacodynamic profiles of pioglitazone in diabetic rats: Impact on therapeutics. Saudi Med J 2021;42(2):151-160. PubMed
  227. Hinkle SN, Gleason JL, Yisahak SF, et al. Assessment of Caffeine Consumption and Maternal Cardiometabolic Pregnancy Complications. JAMA Netw Open 2021;4(11):e2133401. PubMed
  228. Yartsev A, Peisah C. Caffeine-clozapine interaction associated with severe toxicity and multiorgan system failure: a case report. BMC Psychiatry 2021;21(1):192. PubMed
  229. Tinawi M. Severe Rhabdomyolysis Due to Strenuous Exercise With a Potential Role of a High-Caffeine Energy Drink. Cureus 2022;14(1):e20867. PubMed
  230. Gleason JL, Sundaram R, Mitro SD, et al. Association of maternal caffeine consumption during pregnancy with child growth. JAMA Netw Open. 2022;5(10):e2239609. PubMed
  231. Ismail RIH, Awad HA, Saber M, Shehata BM. Bone mineral content for preterm neonates treated with caffeine using dual energy X-ray absorptiometry: An observational study. J Neonatal Perinatal Med 2023;16(1):129-135. PubMed
  232. Zhao J, Huang Y, Yu X. Caffeine intake and the risk of incident kidney stones: a systematic review and meta-analysis. Int Urol Nephrol 2022;54(10):2457-2466. PubMed
  233. Abbas-Hashemi SA, Hosseininasab D, Rastgoo S, Shiraseb F, Asbaghi O. The effects of caffeine supplementation on blood pressure in adults: A systematic review and dose-response meta-analysis. Clin Nutr ESPEN 2023;58:165-177. PubMed
  234. Oliphant EA, Hanning SM, McKinlay CJD, Alsweiler JM. Caffeine for apnea and prevention of neurodevelopmental impairment in preterm infants: systematic review and meta-analysis. J Perinatol 2024;44(6):785-801. PubMed
  235. Kühne T, Wallace E, Herzig D, et al. Combined intake of caffeine and low-dose glucose to reduce exercise-related hypoglycaemia in individuals with type 1 diabetes on ultra-long-acting insulin degludec: A randomized, controlled, double-blind, cross-over tr
  236. Song JJ, Eyabi JC, Awatramani PD, Mitchell BG, Nene SY. Sudden Reduction in Caffeine Intake Increases Serum Lithium Concentration to Supratherapeutic Level: A Case Report. Prim Care Companion CNS Disord 2024;26(2):23cr03642. PubMed

See these in context on the Caffeine monograph →

Yohimbe 66 references
  1. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
  2. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  3. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  4. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  5. Milman N, Scheibel J, Jessen O. Lysine prophylaxis in recurrent herpes simplex labialis: a double-blind, controlled crossover study. Acta Derm Venereol 1980;60:85-7.
  6. Teloken C, Rhoden EL, Sogari P, et al. Therapeutic effects of high dose yohimbine hydrochloride on organic erectile dysfunction. J Urol 1998;159:122-4. PubMed
  7. Jacobsen FM. Fluoxetine-induced sexual dysfunction and an open trial of yohimbine. J Clin Psychiatry 1992;53:119-22.
  8. Hollander E, McCarley A. Yohimbine treatment of sexual side effects induced by serotonin reuptake blockers. J Clin Psychiatry 1992;53:207-9.
  9. Sandler B, Aronson P. Yohimbine-induced cutaneous drug eruption, progressive renal failure, and lupus-like syndrome. Urol 1993;41:343-5. PubMed
  10. Kearney T, Tu N, Haller C. Adverse drug events associated with yohimbine-containing products: a retrospective review of the California Poison Control System reported cases. Ann Pharmacother 2010;44:1022-9. PubMed
  11. VandenBrink, B. M., Foti, R. S., Rock, D. A., Wienkers, L. C., and Wahlstrom, J. L. Prediction of CYP2D6 drug interactions from in vitro data: evidence for substrate-dependent inhibition. Drug Metab Dispos. 2012;40(1):47-53. PubMed
  12. Abebe, W. An overview of herbal supplement utilization with particular emphasis on possible interactions with dental drugs and oral manifestations. J Dent.Hyg. 2003;77(1):37-46.
  13. Mustonen, P., Savola, J., and Lassila, R. Atipamezole, an imidazoline-type alpha(2)-adrenoceptor inhibitor, binds to human platelets and inhibits their adrenaline-induced aggregation more effectively than yohimbine. Thromb.Res 8-1-2000;99(3):231-237.
  14. Cameron, O. G., Zubieta, J. K., Grunhaus, L., and Minoshima, S. Effects of yohimbine on cerebral blood flow, symptoms, and physiological functions in humans. Psychosom.Med 2000;62(4):549-559. PubMed
  15. Bowes, M. P., Peters, R. H., Kernan, W. J., Jr., and Hopper, D. L. Effects of yohimbine and idazoxan on motor behaviors in male rats. Pharmacol.Biochem.Behav. 1992;41(4):707-713.
  16. Bagheri, H., Schmitt, L., Berlan, M., and Montastruc, J. L. Effect of 3 weeks treatment with yohimbine on salivary secretion in healthy volunteers and in depressed patients treated with tricyclic antidepressants. Br J Clin Pharmacol 1992;34(6):555-558. PubMed
  17. Bagheri, H., Bompart, G., Girolami, J. P., Montastruc, J. L., and Montastruc, P. Is yohimbine-induced increase in salivary secretion a kinin-dependent mechanism? Fundam.Clin Pharmacol 1992;6(1):17-20. PubMed
  18. Swann, A. C., Birnbaum, D., Jagar, A. A., Dougherty, D. M., and Moeller, F. G. Acute yohimbine increases laboratory-measured impulsivity in normal subjects. Biol.Psychiatry 5-15-2005;57(10):1209-1211. PubMed
  19. Adeniyi, A. A., Brindley, G. S., Pryor, J. P., and Ralph, D. J. Yohimbine in the treatment of orgasmic dysfunction. Asian J Androl 2007;9(3):403-407. PubMed
  20. Murburg, M. M., Villacres, E. C., Ko, G. N., and Veith, R. C. Effects of yohimbine on human sympathetic nervous system function. J Clin Endocrinol.Metab 1991;73(4):861-865. PubMed
  21. Giampreti, A., Lonati, D., Locatelli, C., Rocchi, L., and Campailla, M. T. Acute neurotoxicity after yohimbine ingestion by a body builder. Clin Toxicol.(Phila) 2009;47(8):827-829. PubMed
  22. Bloomer, R. J., Canale, R. E., Blankenship, M. M., Hammond, K. G., Fisher-Wellman, K. H., and Schilling, B. K. Effect of the dietary supplement Meltdown on catecholamine secretion, markers of lipolysis, and metabolic rate in men and women: a randomized,
  23. Myers, A. and Barrueto, F., Jr. Refractory priapism associated with ingestion of yohimbe extract. J Med Toxicol. 2009;5(4):223-225.
  24. Berlin, I., Crespo-Laumonnier, B., Cournot, A., Landault, C., Aubin, F., Legrand, J. C., and Puech, A. J. The alpha 2-adrenergic receptor antagonist yohimbine inhibits epinephrine-induced platelet aggregation in healthy subjects. Clin Pharmacol.Ther. 199
  25. Swann, A. C. Mechanisms of impulsivity in bipolar disorder and related illness. Epidemiol.Psichiatr.Soc. 2010;19(2):120-130.
  26. Shibao, C., Okamoto, L. E., Gamboa, A., Yu, C., Diedrich, A., Raj, S. R., Robertson, D., and Biaggioni, I. Comparative efficacy of yohimbine against pyridostigmine for the treatment of orthostatic hypotension in autonomic failure. Hypertension 2010;56(5) PubMed
  27. Soeter, M. and Kindt, M. Stimulation of the noradrenergic system during memory formation impairs extinction learning but not the disruption of reconsolidation. Neuropsychopharmacology 2012;37(5):1204-1215. PubMed
  28. Cimolai, N. and Cimolai, T. Yohimbine use for physical enhancement and its potential toxicity. J Diet.Suppl 2011;8(4):346-354. PubMed
  29. Bagheri, H., Berlan, M., Montastruc, J. L., and Montastruc, P. Yohimbine and lacrimal secretion. Br J Clin Pharmacol. 1990;30(1):151-152.
  30. Landis, E. and Shore, E. Yohimbine-induced bronchospasm. Chest 1989;96(6):1424. PubMed
  31. Susset, J. G., Tessier, C. D., Wincze, J., Bansal, S., Malhotra, C., and Schwacha, M. G. Effect of yohimbine hydrochloride on erectile impotence: a double-blind study. J Urol. 1989;141(6):1360-1363. PubMed
  32. Chatelut, E., Rispail, Y., Berlan, M., and Montastruc, J. L. Yohimbine increases human salivary secretion. Br.J Clin Pharmacol. 1989;28(3):366-368. PubMed
  33. Montastruc, P., Berlan, M., and Montastruc, J. L. Effects of yohimbine on submaxillary salivation in dogs. Br J Pharmacol 1989;98(1):101-104. PubMed
  34. Charney, D. S., Price, L. H., and Heninger, G. R. Desipramine-yohimbine combination treatment of refractory depression. Implications for the beta-adrenergic receptor hypothesis of antidepressant action. Arch.Gen.Psychiatry 1986;43(12):1155-1161. PubMed
  35. Braddock, L., Cowen, P. J., Elliott, J. M., Fraser, S., and Stump, K. Binding of yohimbine and imipramine to platelets in depressive illness. Psychol.Med 1986;16(4):765-773. PubMed
  36. Bolme, P., Corrodi, H., Fuxe, K., Hokfelt, T., Lidbrink, P., and Goldstein, M. Possible involvement of central adrenaline neurons in vasomotor and respiratory control. Studies with clonidine and its interactions with piperoxane and yohimbine. Eur J Pharm PubMed
  37. Charney, D. S., Heninger, G. R., and Sternberg, D. E. Assessment of alpha 2 adrenergic autoreceptor function in humans: effects of oral yohimbine. Life Sci 6-7-1982;30(23):2033-2041.
  38. Boon, N. A., Elliott, J. M., Grahame-Smith, D. G., John-Green, T., and Stump, K. A comparison of alpha 2-adrenoreceptor binding characteristics of intact human platelets identified by [3H]-yohimbine and [3H]- dihydroergocryptine. J Auton.Pharmacol 1983;3
  39. Andrejak, M., Ward, M., and Schmitt, H. Cardiovascular effects of yohimbine in anaesthetized dogs. Eur.J Pharmacol 10-28-1983;94(3-4):219-228. PubMed
  40. Brodde, O. E., Anlauf, M., Arroyo, J., Wagner, R., Weber, F., and Buck, K. D. Hypersensitivity of adrenergic receptors and blood-pressure response to oral yohimbine in orthostatic hypotension. N.Engl.J Med 4-28-1983;308(17):1033-1034. PubMed
  41. Charney, D. S., Heninger, G. R., and Redmond, D. E., Jr. Yohimbine induced anxiety and increased noradrenergic function in humans: effects of diazepam and clonidine. Life Sci. 7-4-1983;33(1):19-29. PubMed
  42. Knoll, L. D., Benson, R. C., Jr., Bilhartz, D. L., Minich, P. J., and Furlow, W. L. A randomized crossover study using yohimbine and isoxsuprine versus pentoxifylline in the management of vasculogenic impotence. J Urol. 1996;155(1):144-146. DOI
  43. Betz, J. M., White, K. D., and der Marderosian, A. H. Gas chromatographic determination of yohimbine in commercial yohimbe products. J AOAC Int 1995;78(5):1189-1194. DOI
  44. Bagheri, H., Chale, J. J., Guyen, L. N., Tran, M. A., Berlan, M., and Montastruc, J. L. Evidence for activation of both adrenergic and cholinergic nervous pathways by yohimbine, an alpha 2-adrenoceptor antagonist. Fundam.Clin Pharmacol 1995;9(3):248-254.
  45. Kennedy, S. H., Gnam, W., Ralevski, E., and Brown, G. M. Melatonin responses to clonidine and yohimbine challenges. J Psychiatry Neurosci. 1995;20(4):297-304.
  46. Musso, N. R., Vergassola, C., Pende, A., and Lotti, G. Yohimbine effects on blood pressure and plasma catecholamines in human hypertension. Am J Hypertens. 1995;8(6):565-571. PubMed
  47. Morgan, C. A., III, Southwick, S. M., Grillon, C., Davis, M., Krystal, J. H., and Charney, D. S. Yohimbine-facilitated acoustic startle reflex in humans. Psychopharmacology (Berl) 1993;110(3):342-346. PubMed
  48. Adler, L. E., Hoffer, L., Nagamoto, H. T., Waldo, M. C., Kisley, M. A., and Giffith, J. M. Yohimbine impairs P50 auditory sensory gating in normal subjects. Neuropsychopharmacology 1994;10(4):249-257. PubMed
  49. Biaggioni, I., Robertson, R. M., and Robertson, D. Manipulation of norepinephrine metabolism with yohimbine in the treatment of autonomic failure. J Clin Pharmacol. 1994;34(5):418-423. PubMed
  50. Kenney, W. L., Zappe, D. H., Tankersley, C. G., and Derr, J. A. Effect of systemic yohimbine on the control of skin blood flow during local heating and dynamic exercise. Am J Physiol 1994;266(2 Pt 2):H371-H376. PubMed
  51. Friesen, K., Palatnick, W., and Tenenbein, M. Benign course after massive ingestion of yohimbine. J Emerg.Med 1993;11(3):287-288. PubMed
  52. Bierer, L. M., Aisen, P. S., Davidson, M., Ryan, T. M., Stern, R. G., Schmeidler, J., and Davis, K. L. A pilot study of oral physostigmine plus yohimbine in patients with Alzheimer disease. Alzheimer Dis.Assoc.Disord. 1993;7(2):98-104. PubMed
  53. Mann, K., Klingler, T., Noe, S., Roschke, J., Muller, S., and Benkert, O. Effects of yohimbine on sexual experiences and nocturnal penile tumescence and rigidity in erectile dysfunction. Arch.Sex Behav. 1996;25(1):1-16. PubMed
  54. Rowland, D. L., Kallan, K., and Slob, A. K. Yohimbine, erectile capacity, and sexual response in men. Arch Sex Behav 1997;26(1):49-62.
  55. Bremner, J. D., Innis, R. B., Ng, C. K., Staib, L. H., Salomon, R. M., Bronen, R. A., Duncan, J., Southwick, S. M., Krystal, J. H., Rich, D., Zubal, G., Dey, H., Soufer, R., and Charney, D. S. Positron emission tomography measurement of cerebral metaboli
  56. Riley AJ, Goodman R, Kellett JM, and et al. Double blind trial of yohimbine hydrochloride in the treatment of erection inadequacy. Sexual Marital Ther 1989;4(1):17-26. DOI
  57. Cohen PA, Wang YH, Maller G, DeSouza R, Khan IA. Pharmaceutical quantities of yohimbine found in dietary supplements in the USA. Drug Test Anal. 2015 Sep 22. PubMed
  58. Ruck B, Shih RD, Marcus SM. Hypertensive crisis from herbal treatment of impotence. Am J Emerg Med. 1999;17:317-318. PubMed
  59. Wylie KR. Yohimbine and sinusitis. Br J Psychiatry. 1996;169(3):384-5. PubMed
  60. Le Corre P, Parmer RJ, Kailasam MT, et al. Human sympathetic activation by alpha2-adrenergic blockade with yohimbine: Bimodal, epistatic influence of cytochrome P450-mediated drug metabolism. Clin Pharmacol Ther. 2004;76(2):139-53.
  61. Mueller-Schoell A, Michelet R, Weinelt F, Kloft C, Mikus G. CYP2D6 phenotype explains reported yohimbine concentrations in four severe acute intoxications. Arch Toxicol. 2021. PubMed
  62. Bharucha AE, Skaar T, Andrews CN, et al Relationship of cytochrome P450 pharmacogenetics to the effects of yohimbine on gastrointestinal transit and catecholamines in healthy subjects. Neurogastroenterol Motil. 2008;20(8):891-9. PubMed
  63. Schmauss M, Laakmann G, Dieterle D. Effects of alpha 2-receptor blockade in addition to tricyclic antidepressants in therapy-resistant depression. J Clin Psychopharmacol. 1988;8(2):108-11.
  64. Haron MH, Dale O, Martin K, et al. Evaluation of the Herb-Drug Interaction Potential of Commonly Used Botanicals on the US Market with Regard to PXR- and AhR-Mediated Influences on CYP3A4 and CYP1A2. J Diet Suppl 2022. PubMed
  65. Hodapp B, Haggerty A, Feldman R, Timpe J. Intracranial hemorrhage after a single dose of Yohimbine in a chronic user of clonidine. Am J Emerg Med 2022;62:145. PubMed
  66. Vay M, Meyer MJ, Blank A, et al. Oral yohimbine as a new probe drug to predict CYP2D6 activity: results of a fixed-sequence phase I trial. Clin Pharmacokinet. 2020;59(7):927-939. PubMed

See these in context on the Yohimbe monograph →

Bitter Orange 47 references
  1. Penzak SR, Jann MW, Cold JA, et al. Seville (sour) orange juice: synephrine content and cardiovascular effects in normotensive adults. J Clin Pharmacol 2001;41:1059-63. PubMed
  2. Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=182
  3. Calapai G, Firenzuoli F, Saitta A, et al. Antiobesity and cardiovascular toxic effects of Citrus aurantium extracts in the rat: A preliminary report. Fitoterapia 1999;70:586-92. DOI
  4. Keogh AM, Baron DW. Sympathomimetic abuse and coronary artery spasm. Br Med J 1985;291:940.
  5. Malhotra S, Bailey DG, Paine MF, Watkins PB. Seville orange juice-felodipine interaction: comparison with dilute grapefruit juice and involvement of furocoumarins. Clin Pharmacol Ther 2001;69:14-23. PubMed
  6. Pellati F, Benvenuti S, Melegari M, Firenzuoli F. Determination of adrenergic agonists from extracts and herbal products of Citrus aurantium L. var. amara by LC. J Pharm Biomed Anal 2002;29:1113-9. . PubMed
  7. Colker CM, Kalman DS, Torina GC, et al. Effects of Citrus aurantium extract, caffeine, and St. John's wort on body fat loss, lipid levels, and mood states in overweight healthy adults. Curr Ther Res 1999;60:145-153. DOI
  8. Penzak SR, Acosta EP, Turner M, et al. Effect of Seville orange juice and grapefruit juice on indinavir pharmacokinetics. J Clin Pharmacol 2002;42:1165-70. PubMed
  9. Edwards DJ, Fitzsimmons ME, Schuetz EG, et al. 6',7'-Dihydroxybergamottin in grapefruit juice and Seville orange juice: effects on cyclosporine disposition, enterocyte CYP3A4, and P-glycoprotein. Clin Pharmacol Ther 1999;65:237-44. PubMed
  10. Di Marco MP, Edwards DJ, Wainer IW, Ducharme MP. The effect of grapefruit juice and seville orange juice on the pharmacokinetics of dextromethorphan: the role of gut CYP3A and P-glycoprotein. Life Sci 2002;71:1149-60. PubMed
  11. Visentin V, Morin N, Fontana E, et al. Dual action of octopamine on glucose transport into adipocytes: inhibition via beta3-adrenoceptor activation and stimulation via oxidation by amine oxidases. J Pharmacol Exp Ther 2001;299:96-104.
  12. Nykamp DL, Fackih MN, Compton AL. Possible association of acute lateral-wall myocardial infarction and bitter orange supplement. Ann Pharmacother 2004;38:812-6. PubMed
  13. Fugh-Berman A, Myers A. Citrus aurantium, an ingredient of dietary supplements marketed for weight loss: Current status of clinical and basic Research. Exp Biol Med 2004;229:698-704.
  14. Suzuki O, Matsumoto T, Oya M, Katsumata Y. Oxidation of synephrine by type A and type B monoamine oxidase. Experientia 1979;35:1283-4. PubMed
  15. Nasir JM, Durning SJ, Ferguson M, et al. Exercise-induced syncope associated with QT prolongation and ephedra-free Xenadrine. Mayo Clin Proc 2004;79:1059-62.. PubMed
  16. Firenzuoli F, Gori L, Galapai C. Adverse reaction to an adrenergic herbal extract (Citrus aurantium). Phytomedicine 2005;12:247-8. PubMed
  17. Bouchard NC, Howland MA, Greller HA, et al. Ischemic stroke associated with use of an ephedra-free dietary supplement containing synephrine. Mayo Clin Proc 2005;80:541-5. PubMed
  18. Haller CA, Benowitz NL, Jacob P 3rd. Hemodynamic effects of ephedra-free weight-loss supplements in humans. Am J Med 2005;118:998-1003.. PubMed
  19. Bui LT, Nguyen DT, Ambrose PJ. Blood pressure and heart rate effects following a single dose of bitter orange. Ann Pharmacother 2006;40:53-7. PubMed
  20. Min B, Cios D, Kluger J, White CM. Absence of QTc-interval-prolonging or hemodynamic effects of a single dose of bitter-orange extract in healthy subjects. Pharmacotherapy 2005;25:1719-24. PubMed
  21. Gange CA, Madias C, Felix-Getzik EM, et al. Variant angina associated with bitter orange in a dietary supplement. Mayo Clin Proc 2006;81:545-8. PubMed
  22. Jordan S, Murty M, Pilon K. Products containing bitter orange or synephrine: suspected cardiovascular adverse reactions. Canadian Adverse Reaction Newsletter 2004;14:3-4.
  23. Burke J, Seda G, Allen D, Knee TS. A case of severe exercise-induced rhabdomyolysis associated with a weight loss dietary supplement. Mil Med 2007;172:656-8. PubMed
  24. Gray, S. and Woolf, A. D. Citrus aurantium used for weight loss by an adolescent with anorexia nervosa. J Adolesc.Health 2005;37(5):414-415. PubMed
  25. Haller, C. A., Duan, M., Jacob, P., III, and Benowitz, N. Human pharmacology of a performance-enhancing dietary supplement under resting and exercise conditions. Br J Clin Pharmacol 2008;65(6):833-840. PubMed
  26. Thomas, J. E., Munir, J. A., McIntyre, P. Z., and Ferguson, M. A. STEMI in a 24-year-old man after use of a synephrine-containing dietary supplement: a case report and review of the literature. Tex.Heart Inst.J 2009;36(6):586-590.
  27. Campbell-Tofte, J. I., Molgaard, P., Josefsen, K., Abdallah, Z., Hansen, S. H., Cornett, C., Mu, H., Richter, E. A., Petersen, H. W., Norregaard, J. C., and Winther, K. Randomized and double-blinded pilot clinical study of the safety and anti-diabetic ef
  28. Seifert, J. G., Nelson, A., Devonish, J., Burke, E. R., and Stohs, S. J. Effect of acute administration of an herbal preparation on blood pressure and heart rate in humans. Int J Med Sci 2011;8(3):192-197. PubMed
  29. Stohs, S. J., Preuss, H. G., Keith, S. C., Keith, P. L., Miller, H., and Kaats, G. R. Effects of p-synephrine alone and in combination with selected bioflavonoids on resting metabolism, blood pressure, heart rate and self-reported mood changes. Int J Med
  30. Wason, S., DiGiacinto, J. L., and Davis, M. W. Effects of grapefruit and Seville orange juices on the pharmacokinetic properties of colchicine in healthy subjects. Clin Ther 2012;34(10):2161-2173. PubMed
  31. Kaats, G. R., Miller, H., Preuss, H. G., and Stohs, S. J. A 60day double-blind, placebo-controlled safety study involving Citrus aurantium (bitter orange) extract. Food Chem Toxicol. 2013;55:358-362.
  32. Calapai, G., Firenzuoli, F., Saitta, A., Squadrito, F. R., Arlotta, M., Costantino, G., and Inferrera, G. Antiobesity and cardiovascular toxic effects of Citrus aurantium extracts in the rat: a preliminary report. Fitoterapia 12-1-1999;70(6):586-592. DOI
  33. Colker, C., Kalman, D., and Torina, G. Effects of Citrus aurantium extract, caffeine, and St. John's Wort on body fat loss, lipid levels, and mood states in overweight healthy adults. Curr Ther Res 1999;60:145-153. DOI
  34. Shara M, Stohs SJ. Safety evaluation of Bitter orange extract (p-synephrine) in healthy volunteers. J.Amer.Coll.Nutr. 2011;30:358.
  35. Lynch B. Review of the safety of p-synephrine and caffeine. Intertek-Cantox Report, 2013;1-20.
  36. Smith TB, Staub BA, Natarajan GM, et al. Acute myocardial infarction associated with dietary supplements containing 1,3-dimethylamylamine and Citrus aurantium. Tex Heart Inst J 2014;41(1):70-2. PubMed
  37. Shara M, Stohs SJ, Mukattash TL. Cardiovascular safety of oral p-synephrine (bitter orange) in healthy subjects: a randomized placebo-controlled cross-over clinical trial. Phytother Res. 2016;30(5):842-7.
  38. Liu Y, Santillo MF. Cytochrome P450 2D6 and 3A4 enzyme inhibition by amine stimulants in dietary supplements. Drug Test Anal. 2016;8(3-4):307-10. PubMed
  39. Abdelkawy KS, Donia AM, Turner RB, Elbarbry F. Effects of Lemon and Seville Orange Juices on the Pharmacokinetic Properties of Sildenafil in Healthy Subjects. Drugs R D. 2016 Sep;16(3):271-278. PubMed
  40. Gutiérrez-Hellín J, Salinero JJ, Abían-Vicen J, Areces F, Lara B, Gallo C, et al. Acute consumption of p-synephrine does not enhance performance in sprint athletes.J. Appl Physiol Nutr Metab. 2016;41(1):63-9. doi: 10.1139/apnm-2015-0299.
  41. Jung YP, Earnest CP, Koozehchian M, et al. Effects of ingesting a pre-workout dietary supplement with and without synephrine for 8 weeks on training adaptations in resistance-trained males. J Int Soc Sports Nutr. 2017;3;14:1. doi: 10.1186/s12970-016-0158- PubMed
  42. Jung YP, Earnest CP, Koozehchian M, et al. Effects of acute ingestion of a pre-workout dietary supplement with and without synephrine on resting energy expenditure, cognitive function and exercise performance. J Int Soc Sports Nutr. 2017;14:3. doi: 10.118
  43. Vatsavai LK, Kilari EK. Interaction of p-synephrine on the pharmacodynamic and pharmacokinetics of gliclazide in animal models. J Ayurveda Integr Med 2017; S0975-9476(16)30487-9. doi: 10.1016/j.jaim.2017.04.010.
  44. Ratamess NA, Bush JA, Stohs SJ, et al. Acute cardiovascular effects of bitter orange extract (p-synephrine) consumed alone and in combination with caffeine in human subjects: A placebo-controlled, double-blind study. Phytother Res. 2018;32(1):94-102.
  45. Gutiérrez-Hellín J, Ruiz-Moreno C, Del Coso J. Acute p-synephrine ingestion increases whole-body fat oxidation during 1-h of cycling at Fatmax. Eur J Nutr. 2019 Nov 5. PubMed
  46. Karimzadeh Z, Azizzadeh Forouzi M, Tajadini H, Ahmadinejad M, Roy C, Dehghan M. Effects of lavender and Citrus aurantium on pain of conscious intensive care unit patients: a parallel randomized placebo-controlled trial. J Integr Med 2021:S2095-4964(21)000 PubMed
  47. Koncz D, Tóth B, Bahar MA, Roza O, Csupor D. The Safety and Efficacy of Citrus aurantium (Bitter Orange) Extracts and p-Synephrine: A Systematic Review and Meta-Analysis. Nutrients 2022;14(19):4019. PubMed

See these in context on the Bitter Orange monograph →

Hordenine 3 references
  1. Barwell CJ, Basma AN, Lafi MA, Leake LD. Deamination of hordenine by monoamine oxidase and its action on vasa deferentia of the rat. J Pharm Pharmacol 1989;41(6):421-3. PubMed
  2. Nelson BC, Putzbach K, Sharpless KE, Sander LC. Mass spectrometric determination of the predominant adrenergic protoalkaloids in bitter orange (Citrus aurantium). J Agric Food Chem 2007;55(24):9769-75. PubMed
  3. Liu Y, Santillo MF. Cytochrome P450 2D6 and 3A4 enzyme inhibition by amine stimulants in dietary supplements. Drug Test Anal. 2016;8(3-4):307-10. PubMed

See these in context on the Hordenine monograph →

Tyramine 15 references
  1. Pawar RS, Grundel E. Overview of regulation of dietary supplements in the USA and issues of adulteration with phenethylamines (PEAs). Drug Test Anal 2017;9:500-517. PubMed
  2. Smedema JP, Müller GJ. Coronary spasm and thrombosis in a bodybuilder using a nutritional supplement containing synephrine, octopamine, tyramine and caffeine. S Afr Med J. 2008;98(5):372-3.
  3. Gilliam LK, Palmer JP, Taborsky GJ Jr. Tyramine-mediated activation of sympathetic nerves inhibits insulin secretion in humans. J Clin Endocrinol Metab. 2007;92(10):4035-8. PubMed
  4. VanDenBerg CM, Blob LF, Kemper EM, Azzaro AJ. Tyramine pharmacokinetics and reduced bioavailability with food. J Clin Pharmacol. 2003;43(6):604-9. DOI
  5. Meck JV, Martin DS, D'Aunno DS, Waters WW. Pressor response to intravenous tyramine is a marker of cardiac, but not vascular, adrenergic function. J Cardiovasc Pharmacol. 2003;41(1):126-31. PubMed
  6. Peet M, Yates RA, Carroll JA, Middlemiss DN. The interaction of tyramine with a single dose of tranylcypromine in healthy volunteers. Br J Clin Pharmacol. 1981;11(2):212-4. PubMed
  7. Del Rio B, Redruello B, Linares DM, et al. The dietary biogenic amines tyramine and histamine show synergistic toxicity towards intestinal cells in culture. Food Chem. 2017;218:249-255. PubMed
  8. Linares DM, del Rio B, Redruello B, et al. Comparative analysis of the in vitro cytotoxicity of the dietary biogenic amines tyramine and histamine. Food Chem. 2016;197(Pt A):658-63. PubMed
  9. National Institutes of Health. Dietary Supplement Label Database. http://www.dsld.nlm.nih.gov/dsld/rptQSearch.jsp?item=tyramine&db=adsld. Accessed October 23, 2019.
  10. Rapaport MH. Dietary restrictions and drug interactions with monoamine oxidase inhibitors: the state of the art. J Clin Psychiatry. 2007;68 Suppl 8:42-6.
  11. Colombo F, Porro T, del Rosso G, Bertalero P, Orlandi L, Libretti A. Cardiovascular responses to physical exercise and tyramine infusion in hypertensive and normotensive subjects. J Hum Hypertens. 1989;3(4):245-9.
  12. Pace DG, Reele SB, Rozik LM, Rogers-Phillips CA, Dabice JA, Givens SV. Evaluation of methods of administering tyramine to raise systolic blood pressure. Clin Pharmacol Ther. 1988;44(2):137-44. PubMed
  13. Caston JC, Eaton CL, Gheorghiu BP, Ware LL. Tyramine induced hypertensive episodes and panic attacks in hereditary deficient monoamine oxidase patients: case reports. J S C Med Assoc. 2002;98(4):187-92.
  14. European Food Safety Authority. Scientific opinion on risk based control of biogenic amine formation in fermented foods. EFSA Journal. 2011;9(10):2393. DOI
  15. Rafehi M, Faltraco F, Matthaei J, et al. Highly variable pharmacokinetics of tyramine in humans and polymorphisms in OCT1, CYP2D6, and MAO-A. Front Pharmacol. 2019 Oct 30;10:1297. PubMed

See these in context on the Tyramine monograph →

Phenethylamine (pea) 9 references
  1. Singhal AB, Caviness VS, Begleiter AF, et al. Cerebral vasoconstriction and stroke after use of serotonergic drugs. Neurology 2002;58:130-3. PubMed
  2. Sabelli H, Fink P, Fawcett J, et al. Sustained antidepressant effect of PEA replacement. J Neuropsychiatry Clin Neurosci. 1996;8(2):168-71.
  3. Xie Z, Miller G. Beta-phenylehtylamine alters monoamine transporter function via trace amine-associated receptor 1: implication for modulatory roles of trace amines in brain. J Pharmacol Exp Ther. 2008;325(2):617-28.
  4. Lukasik-Glebocka M, Sommerfeld K, Tezyk A, et al. [Acute poisoning with weight-loss dietary supplement falsely suggesting the use of amphetamine]. Przegl Lek. 2013;70(10):880-3.
  5. Nakamura M, Ishii A, Nakahara D. Characterization of beta-phenyltheylamine-induced monoamine release in rat nucleus accumbens: a microdialysis study. Eur J Pharmacol. 1998;349(2-3):163-9.
  6. Bailey B, Philips S, Boulton A. In vivo release of endogenous dopamine, 5-hydroxytryptamine and some of their metabolites from rat caudate nucleus by phenylethylamine. Neurochem Res. 1987;12(2):173-8. PubMed
  7. Mantegazza P, Riva M. Amphetamine-like activity of beta-phenethylamine after a monoamine oxidase inhibitor in vivo. Journal of Pharmacy and Pharmacology. 1963;151(1):472-8.
  8. Grimsby J, Toth M, Chen K, et al. Increased stress response and beta-phenylethylamine in MAOB-deficient mice. Nat Genet. 1997;17(2):206-10.
  9. Lindemann L, Hoener MC. A renaissance in trace amines inspired by a novel GPCR family. Trends Pharmacol Sci. 2005;26(5):274-81. PubMed

See these in context on the Phenethylamine (pea) monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Supplement interaction checker › Check any supplement or product against your medications Drug–drug interactions › Check two or more of your medications against each other Browse medications A–Z › Every drug we've checked against herbs & supplements NDC & pricing lookup › Find a drug’s NDCs, packaging and costs Ask a pharmacist › Free, personal answer from our licensed team