Major interaction on record — check this product against your medications before combining. Check your meds →
Dietary supplement

Creatine Energy Unflavored Ingredients & Drug Interactions

by FINAFLEX

Creatine Energy Unflavored label
See full label image
Powder Category: Other Combinations
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 Creatine Energy Unflavored 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

Creatine Energy Unflavored is a dietary supplement by FINAFLEX with 2 active ingredients. Its ingredients are commonly taken for mental alertness and reducing fatigue, improving athletic performance, headache and migraine relief.Based on those ingredients, 655 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are 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 Creatine Energy Unflavored by FINAFLEX

Ask about any prescription or over-the-counter medication and we check it for interactions with Creatine Energy Unflavored by FINAFLEX — 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 Creatine Energy Unflavored by FINAFLEX

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 Jul 23, 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 1 of its 5 active ingredients.
  • “Creatine Matrix” is a proprietary blend — the label gives one combined amount (5 Gram(s)) without saying how much of each component you get.

Creatine Energy Unflavored contains 5 active ingredients: caffeine anhydrous for mental alertness and energy, plus four forms of creatine (Creatine Anhydrous, Creatine Citrate, Creapure, and Crea-Trona) to support muscle strength and athletic performance. The product also contains silica as an inactive ingredient.

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: Athletic performance and muscle strength support.
  • We looked for evidence on: Athletic performance, Exercise-induced muscle soreness, Muscle strength, Physical performance, Muscle breakdown, Sarcopenia — and 3 related terms.
  • The strongest evidence on file: Caffeine is rated "Likely Effective" for Athletic performance (Natural Medicines).
  • Also on file: Creatine is rated "Possibly Effective" for Athletic performance, Muscle strength, Sarcopenia.
  • Also on file: Creatine is rated "Insufficient Reliable Evidence To Rate" for Muscle breakdown, Physical performance.

Caffeine is effective for mental alertness and athletic performance, and likely effective for boosting focus and endurance. The creatine blend is possibly effective for muscle strength, athletic performance, and sarcopenia (age-related muscle loss).

Evidence is less clear for creatine's role in certain neurological conditions like Huntington disease and bone health, where it appears possibly ineffective based on available studies.

The evidence, ingredient by ingredient Caffeine Creatine

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 2 of the 2 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 2 of 2.
  • General safety write-ups exist for 2 of 2.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Caffeine is generally well tolerated in moderate amounts for healthy adults, but high doses can cause serious side effects. Common side effects include anxiety, insomnia, tremors, nausea, diarrhea, and restlessness.

A small number of trial participants reported anaphylaxis (severe allergic reaction), though true caffeine allergy is rare. Creatine is generally well tolerated in healthy adults but those with kidney problems should be cautious.

The most common side effects are dehydration, diarrhea, gastrointestinal upset, muscle cramps, and water retention. Rare but serious concerns from case reports include kidney injury and muscle breakdown (rhabdomyolysis).

Side effects, ingredient by ingredient Caffeine Creatine

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?
  • 1 of the 2 matched ingredients can interact with medications — Caffeine.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; diabetes medications; lithium.
  • For scale: 655 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 you take this, double-check if you use ephedrine or ephedra (Major interaction risk). Also screen yourself for pentobarbital, dipyridamole, clozapine, cimetidine, quinolone antibiotics, phenobarbital, or carbamazepine—all Moderate interactions with the caffeine.

Your doctor or pharmacist can help you weigh the risks if you're on any of these.

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.

This product is best for healthy adults looking to boost mental energy and athletic performance. If you take any stimulants, sleep aids, anticonvulsants, antipsychotics, antibiotics, or stomach medications, check your exact drug names with a tool on this page or talk to your doctor or pharmacist before starting.

People with kidney disease should be especially careful with the creatine content. Pregnancy and nursing mothers should avoid this product—safety data is not established for either.

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

Assessment coverage: 5 of 5 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Jun 25, 2018.

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 Creatine Energy Unflavored, straight from the product label.

Brand FINAFLEX
Barcode (UPC) 689466777093
Net contents 11 Oz(s); 312 Gram(s)
Market status On market
Date entered into DSLD Jun 25, 2018
DSLD ID 178073
Product type Other Combinations
Supplement form Powder
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 Creatine Energy Unflavored by FINAFLEX, 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:
5 Gram(s)
Maximum serving Sizes:
5 Gram(s)
Servings per container
60
UPC/BARCODE
689466777093
IngredientAmount% DV
Caffeine Anhydrous100 mg--
Creatine Anhydrous0 NP--
Creatine Citrate0 NP--
Creapure0 NP--
Crea-Trona0 NP--
Creatine Matrix5 Gram(s)--

Other ingredients: Silica

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.
Suggested/Recommended/Usage/Directions

Suggested use: As a dietary supplement, consume 1 scoop of Creatine Energy daily. Add 1 scoop to 8-16 ounces of water or your favorite flavored beverage and consume immediately after stirring. Drink Creatine Energy every day to ensure proper creatine supplementation. Do not exceed 4 scoops daily.

Shake container prior to use to redistribute ingredients.

Use FinaFlex Creatine Energy to increase muscle strength and help power through daily workouts.

Precautions

Do not exceed 4 scoops daily.

Warning: Keep out of reach of children.

Do not use if pregnant or nursing.

Consult your doctor prior to use if you have or are at risk for prostate disease, heart disease, or any other general medical condition.

All persons are advised to consult with their doctor or other medical authority before use of this or any other dietary supplement. Discuss possible interactions and contradictions of this dietary supplement with other medicines currently prescribed by your doctor.

Discontinue use immediately if you experience any adverse symptoms or reactions while taking this product. Discontinue use 2 weeks prior to surgery. Do not use if your health status is unknown.

May not be suitable for persons under the age of 18 years old.

Do not discard desiccant after opening.

FDA Statement of Identity

Dietary Supplement - 312 grams

Dietary Supplement

General Statements

Contents may settle in transit.

Made in USA

Sport performance Increase strength and power Promotes energy levels Clean energy 60 servings

Storage

Store in a cool dry place (heat and humidity can cause clumping).

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.

Formula

Caffeine + Creatine Matrix

Ultimate Creatine Energy Matrix Powered by Creapure

Creatine Energy combines a uniquely formulated Creatine Matrix with a low level of caffeine per scoop to promote increased energy levels during exercise.

Creatine Energy contains two of the purest forms of Creatine available today, Creapure and Crea-Trona. These two unique Creatines are manufactured under strict GMP (Good Manufacturing Practice) engineering processes in Germany with the end result being two refined and robust ingredients both guaranteed by sophisticated analytical analyses to be of the highest quality.

Brand IP Statement(s)

Redefine yourself

Creapure and Crea-Trona are registered trademarks of Alzchem Trostberg GmbH.

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

See for yourself

Creatine Energy Unflavored by FINAFLEX label

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

Creatine Energy Unflavored 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 Creatine Energy Unflavored by FINAFLEX

These are the 2 active ingredients this product is made of. Select any to open its full monograph.

Serving size5 Gram(s) Dosage formPowder Servings per container60 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
100 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

Creatine Matrix

No known
interactions
5 Gram(s) per serving

Creatine is one of the most studied sports supplements, with solid evidence that it can boost strength and performance during short, high-intensity ac...

Creatine Matrix monograph & interactions

Other (inactive) ingredients: Silica. These complete the product’s ingredient list but are not active constituents.

Interaction report

Creatine Energy Unflavored by FINAFLEX Drug Interactions

Want to check YOUR meds against Creatine Energy Unflavored?

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
655Drugs
8 Major 483 Moderate 164 Minor

Ingredients driving the most interactions

Caffeine Anhydrous 655

Individual Drug Interactions

The ingredients in Creatine Energy Unflavored interact with 655 drugs. Click any drug to see the details.

1 of the 2 ingredients in Creatine Energy Unflavored interact with drugs. Each result below shows which ingredient is responsible. Caffeine Anhydrous

Each ingredient & the kinds of drugs it affects

For each ingredient in Creatine Energy Unflavored with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

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
The maker

Brand information

Manufacturer and brand details for Creatine Energy Unflavored, from the product label.

FINAFLEX

See all FINAFLEX products
Name
FinaFlex
Street Address
1190 Tidwell Road, Ste 304
City
Alpharetta
State
GA
ZipCode
30004
Web Address
www.FinaFlex.com
Pharmacist Counseling Corner

Creatine Energy Unflavored by FINAFLEX: Common Questions

Does Creatine Energy Unflavored by FINAFLEX interact with any medications?
Yes. Based on its ingredients, Creatine Energy Unflavored has a known interaction with 655 medications, including 8 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Creatine Energy Unflavored contains 2 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.
Will this work for building muscle?
The creatine in this formula is possibly effective for muscle strength and athletic performance. Most people who supplement with creatine see modest gains in strength and power output when combined with resistance training, though individual results vary.
Can I take this if I have kidney problems?
No. The creatine ingredients require caution if you have kidney disease, and safety data is limited in that population. Talk with your doctor before using this product if you have any kidney concerns.
Is it safe during pregnancy or breastfeeding?
No. Safety hasn't been established for either pregnancy or nursing mothers, so the data advises against use. If you're pregnant or nursing, check with your doctor or pharmacist about whether this product is right for you.
What are the most common side effects?
From caffeine: anxiety, insomnia, jitteriness, tremors, nausea, and diarrhea. From creatine: dehydration, stomach upset, muscle cramps, and water retention. These tend to be mild and improve as your body adjusts.
How much caffeine is in one serving?
The product facts provided don't specify the exact caffeine dose per serving. Check the label on your container or contact the manufacturer for the precise amount.

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

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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.

Creatine Energy Unflavored label
Go deeper

The Full Monographs Behind Creatine Energy Unflavored’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

Creatine

Creatine is one of the most studied sports supplements, with solid evidence that it can boost strength and performance during short, high-intensity activities like weightlifting and sprintin...

Read the full Creatine monograph →
Sources

Sources & How We Checked

Creatine Energy Unflavored'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 322 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.

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 →

Creatine 86 references
  1. Koshy KM, Griswold E, Schneeberger EE. Interstitial nephritis in a patient taking creatine. N Engl J Med 1999;340:814-5. PubMed
  2. 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.
  3. Greenhaff P. Renal dysfunction accompanying oral creatine supplements. Lancet 1998;352:233-4. PubMed
  4. Vandenberghe K, Goris M, Van Hecke P, et al. Long-term creatine intake is beneficial to muscle performance during resistance training (abstract). J Appl Physiol 1997;83:2055-63. PubMed
  5. Hultman E, Soderlund K, Timmons JA, et al. Muscle creatine loading in men. J Appl Physiol 1996;81:232-7. PubMed
  6. Pritchard NR, Kalra PA. Renal dysfunction accompanying oral creatine supplements. Lancet 1998;351:1252-3. PubMed
  7. Poortmans JR, Auquier H, Renaut V, et al. Effect of short-term creatine supplementation on renal responses in men (abstract). Eur J Appl Physiol Occup Physiol 1997;76:566-7. PubMed
  8. Poortmans JR, Francaux M. Long-term oral creatine supplementation does not impair renal function in healthy athletes. Med Sci Sports Exerc 1999;31:1108-10. PubMed
  9. Mihic S, MacDonald JR, McKenzie S, Tarnopolsky MA. Acute creatine loading increases fat-free mass, but does not affect blood pressure, plasma creatinine, or CK activity in men and women. Med Sci Sports Exerc 2000;32:291-6. PubMed
  10. Rawson ES, Wehnert ML, Clarkson PM. Effects of 30 days of creatine ingestion in older men. Eur J Appl Physiol Occup Physiol 1999;80:139-44. PubMed
  11. Earnest CP, Almada AL, Mitchell TL. High-performance capillary electrophoresis-pure creatine monohydrate reduces blood lipids in men and women. Clin Sci (Colch) 1996;91:113-8. PubMed
  12. Juhn MS. Oral creatine supplementation. Separating fact from hype. Phys Sportsmed 1999;27:47-50,53-54,56,61,89. PubMed
  13. Juhn MS, O'Kane JW, Vinci DM. Oral creatine supplementation in male collegiate athletes: a survey of dosing habits and side effects. J Am Diet Assoc 1999;99:593-5.
  14. Green AL, Hultman E, Macdonald IA, et al. Carbohydrate ingestion augments skeletal muscle creatine accumulation during creatine supplementation in humans. Am J Physiol 1996;271:E821-6. PubMed
  15. Balsom PD, Soderlund K, Sjodin B, Ekblom B. Skeletal muscle metabolism during short duration high-intensity exercise: influence of creatine supplementation. Acta Physiol Scand 1995;154:303-10. PubMed
  16. Snow RJ, McKenna MJ, Selig SE, et al. Effect of creatine supplementation on sprint exercise performance and muscle metabolism. (abstract) J Appl Physiol 1998;84:1667-73. PubMed
  17. McNaughton LR, Dalton B, Tarr J. The effects of creatine supplementation on high-intensity exercise performance in elite performers. (abstract) Eur J Appl Physiol Occup Physiol 1998;78:236-40. PubMed
  18. Groeneveld GJ, Veldink JH, van der Tweel I, et al. A randomized sequential trial of creatine in amyotrophic lateral sclerosis. Ann Neurol 2003;53:437-45. . PubMed
  19. Robinson SJ. Acute quadriceps compartment syndrome and rhabdomyolysis in a weight lifter using high-dose creatine supplementation. J Am Board Fam Pract 2000;13:134-7. PubMed
  20. Kammer RT. Lone atrial fibrillation associated with creatine monohydrate supplementation. Pharmacotherapy 2005;25:762-4. PubMed
  21. Gualano B, Ugrinowitsch C, Novaes RB, et al. Effects of creatine supplementation on renal function: a randomized, double-blind, placebo-controlled clinical trial. Eur J Appl Physiol 2008;103:33-40. PubMed
  22. Pfeffer, G., Majamaa, K., Turnbull, D. M., Thorburn, D., and Chinnery, P. F. Treatment for mitochondrial disorders. Cochrane Database.Syst.Rev. 2012;4:CD004426. PubMed
  23. 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
  24. Kreider, R. B. Dietary supplements and the promotion of muscle growth with resistance exercise. Sports Med 1999;27(2):97-110. PubMed
  25. Juhn, M. S., O'Kane, J. W., and Vinci, D. M. Oral creatine supplementation in male collegiate athletes: a survey of dosing habits and side effects. J Am.Diet.Assoc 1999;99(5):593-595.
  26. Volek, J. S., Duncan, N. D., Mazzetti, S. A., Putukian, M., Gomez, A. L., and Kraemer, W. J. No effect of heavy resistance training and creatine supplementation on blood lipids. Int J Sport Nutr.Exerc.Metab 2000;10(2):144-156. PubMed
  27. Robinson, T. M., Sewell, D. A., Casey, A., Steenge, G., and Greenhaff, P. L. Dietary creatine supplementation does not affect some haematological indices, or indices of muscle damage and hepatic and renal function. Br.J Sports Med 2000;34(4):284-288. PubMed
  28. Tarnopolsky, M. A. Potential benefits of creatine monohydrate supplementation in the elderly. Curr.Opin.Clin Nutr.Metab Care 2000;3(6):497-502. PubMed
  29. Tarnopolsky, M. A. and MacLennan, D. P. Creatine monohydrate supplementation enhances high-intensity exercise performance in males and females. Int J Sport Nutr.Exerc.Metab 2000;10(4):452-463. PubMed
  30. Arciero, P. J., Hannibal, N. S., III, Nindl, B. C., Gentile, C. L., Hamed, J., and Vukovich, M. D. Comparison of creatine ingestion and resistance training on energy expenditure and limb blood flow. Metabolism 2001;50(12):1429-1434. PubMed
  31. Chrusch, M. J., Chilibeck, P. D., Chad, K. E., Davison, K. S., and Burke, D. G. Creatine supplementation combined with resistance training in older men. Med Sci.Sports Exerc. 2001;33(12):2111-2117. PubMed
  32. Cox, G., Mujika, I., Tumilty, D., and Burke, L. Acute creatine supplementation and performance during a field test simulating match play in elite female soccer players. Int J Sport Nutr.Exerc.Metab 2002;12(1):33-46. PubMed
  33. Kilduff, L. P., Vidakovic, P., Cooney, G., Twycross-Lewis, R., Amuna, P., Parker, M., Paul, L., and Pitsiladis, Y. P. Effects of creatine on isometric bench-press performance in resistance-trained humans. Med Sci.Sports Exerc. 2002;34(7):1176-1183. PubMed
  34. Brose, A., Parise, G., and Tarnopolsky, M. A. Creatine supplementation enhances isometric strength and body composition improvements following strength exercise training in older adults. J Gerontol A Biol.Sci.Med Sci. 2003;58(1):11-19. PubMed
  35. Volek, J. S., Ratamess, N. A., Rubin, M. R., Gomez, A. L., French, D. N., McGuigan, M. M., Scheett, T. P., Sharman, M. J., Hakkinen, K., and Kraemer, W. J. The effects of creatine supplementation on muscular performance and body composition responses to
  36. Tyler, T. F., Nicholas, S. J., Hershman, E. B., Glace, B. W., Mullaney, M. J., and McHugh, M. P. The effect of creatine supplementation on strength recovery after anterior cruciate ligament (ACL) reconstruction: a randomized, placebo-controlled, double-b DOI
  37. Groeneveld, G. J., Beijer, C., Veldink, J. H., Kalmijn, S., Wokke, J. H., and van den Berg, L. H. Few adverse effects of long-term creatine supplementation in a placebo-controlled trial. Int J Sports Med 2005;26(4):307-313. PubMed
  38. Astorino, T. A., Marrocco, A. C., Gross, S. M., Johnson, D. L., Brazil, C. M., Icenhower, M. E., and Kneessi, R. J. Is running performance enhanced with creatine serum ingestion? J Strength.Cond.Res 2005;19(4):730-734. PubMed
  39. Cramer, J. T., Stout, J. R., Culbertson, J. Y., and Egan, A. D. Effects of creatine supplementation and three days of resistance training on muscle strength, power output, and neuromuscular function. J Strength.Cond.Res 2007;21(3):668-677. PubMed
  40. Young, P., De, Jonghe P., Stogbauer, F., and Butterfass-Bahloul, T. Treatment for Charcot-Marie-Tooth disease. Cochrane.Database.Syst.Rev. 2008;(1):CD006052. PubMed
  41. Ostojic, S. M. and Ahmetovic, Z. Gastrointestinal distress after creatine supplementation in athletes: are side effects dose dependent? Res.Sports Med. 2008;16(1):15-22. PubMed
  42. Whitt, K. N., Ward, S. C., Deniz, K., Liu, L., Odin, J. A., and Qin, L. Cholestatic liver injury associated with whey protein and creatine supplements. Semin.Liver Dis. 2008;28(2):226-231. PubMed
  43. Koenig CA, Benardot D Cody M Thompson WR. Comparison of creatine monohydrate and carbohydrate supplementation on repeated jump height performance. J Strength Cond Res. 2008;22(4):1081-1086. PubMed
  44. Gordon, P. H., Cheung, Y. K., Levin, B., Andrews, H., Doorish, C., Macarthur, R. B., Montes, J., Bednarz, K., Florence, J., Rowin, J., Boylan, K., Mozaffar, T., Tandan, R., Mitsumoto, H., Kelvin, E. A., Chapin, J., Bedlack, R., Rivner, M., McCluskey, L.
  45. Bender, A., Samtleben, W., Elstner, M., and Klopstock, T. Long-term creatine supplementation is safe in aged patients with Parkinson disease. Nutr.Res. 2008;28(3):172-178. PubMed
  46. Parness, J. You're "hot" from pumping iron? Anesth.Analg. 2009;108(3):711-713. PubMed
  47. Gualano, B., Ferreira, D. C., Sapienza, M. T., Seguro, A. C., and Lancha, A. H., Jr. Effect of short-term high-dose creatine supplementation on measured GFR in a young man with a single kidney. Am.J.Kidney Dis. 2010;55(3):e7-e9. PubMed
  48. Saidi, H. and Mani, M. Severe metabolic acidosis secondary to coadministration of creatine and metformin, a case report. Am.J.Emerg.Med. 2010;28(3):388-6. PubMed
  49. Gualano, B., de, Salles Painelli, V, Roschel, H., Lugaresi, R., Dorea, E., Artioli, G. G., Lima, F. R., da Silva, M. E., Cunha, M. R., Seguro, A. C., Shimizu, M. H., Otaduy, M. C., Sapienza, M. T., da Costa, Leite C., Bonfa, E., and Lancha Junior, A. H.
  50. Neves, M., Jr., Gualano, B., Roschel, H., Lima, F. R., Lucia, de Sa-Pinto, Seguro, A. C., Shimizu, M. H., Sapienza, M. T., Fuller, R., Lancha, A. H., Jr., and Bonfa, E. Effect of creatine supplementation on measured glomerular filtration rate in postmeno
  51. Gufford, B. T., Sriraghavan, K., Miller, N. J., Miller, D. W., Gu, X., Vennerstrom, J. L., and Robinson, D. H. Physicochemical characterization of creatine N-methylguanidinium salts. J.Diet.Suppl 2010;7(3):240-252.
  52. Lugaresi, R., Leme, M., de, Salles Painelli, V, Murai, I. H., Roschel, H., Sapienza, M. T., Lancha Junior, A. H., and Gualano, B. Does long-term creatine supplementation impair kidney function in resistance-trained individuals consuming a high-protein di
  53. Poortmans, J. R. and Francaux, M. Renal dysfunction accompanying oral creatine supplements. Lancet 7-18-1998;352(9123):234. PubMed
  54. Maganaris, C. N. and Maughan, R. J. Creatine supplementation enhances maximum voluntary isometric force and endurance capacity in resistance trained men. Acta Physiol Scand. 1998;163(3):279-287. PubMed
  55. Vandebuerie, F., Vanden Eynde, B., Vandenberghe, K., and Hespel, P. Effect of creatine loading on endurance capacity and sprint power in cyclists. Int J Sports Med 1998;19(7):490-495. PubMed
  56. Juhn, M. S. and Tarnopolsky, M. Oral creatine supplementation and athletic performance: a critical review. Clin J Sport Med 1998;8(4):286-297. PubMed
  57. Vandenberghe K, Van Hecke P, Van Leemputte M, and et al. Inhibition of muscle phosphocreatine resynthesis by caffeine after creatine loading. Med Sci Sports Exerc 1997;29(5 Supplement):249.
  58. Ziegenfuss T, Lowery LM, and Lemon PW. Acute fluid volume changes in men during three days of creatine supplementation. J Exerc Physiol Online 1998;1(3): .
  59. Kuehl K, Goldberg L, and Elliot D. Renal insufficiency after creatine supplementation in a college football athlete. Med Sci Sports Exerc 1998;30(5 Suppl ):S235. DOI
  60. Balsom PD, Ekblom B, Soderlund K, and et al. Creatine supplementation and dynamic high-intensity intermittent excercise. Scand J Med Sci Sports 1993;3:143-149.
  61. Kirksey KB, Warren BJ, Stone MH, and et al. The effects of six weeks of creatine monohydrate supplementation in male and female track athletes. Med Sci Sports Exerc 1997;29(5 Suppl):S145.
  62. Kreider R, Ransom J, Rasmussen C, and et al. Creatine supplementation during pre-season football does not affect markers of renal function. 83rd Annual Experimental Biology Meeting 1999;
  63. Rasmussen C, Kreider R, Ransom J, and et al. Creatine supplementation during pre-season football training does not affect fluid or electrolyte status. 46th Annual American College of Sports Medicine Annual Meeting 1999; DOI
  64. Tan CW, Hae Tha M, Joo Ng H. Creatine supplementation and venous thrombotic events. Am J Med 2014;127(8):e7-8. PubMed
  65. Young C, Oladipo O, Frasier S, et al. Hemorrhagic stroke in young healthy male following use of sports supplement Jack3d. Mil Med 2012;177(12):1450-4. PubMed
  66. Vilella AL, Limsuwat C, Williams DR, Seifert CF. Cholestatic jaundice as a result of combination designer supplement ingestion. Ann Pharmacother 2013;47(7-8):e33. PubMed
  67. Li N, Hauser R, Holford T, et al. Muscle-building supplement use and increased risk of testicular germ cell cancer in men from Connecticut and Massachusetts. Br J Cancer 2015;112(7):1247-50. PubMed
  68. Centers for Disease Control and Prevention (CDC). Hyperthermia and dehydration-related deaths associated with rapid weight loss in three collegiate wrestlers - North Carolina, Wisconsin, and Michigan, November-December 1997. MMWR Morb Mortal Wkly Rep 1998
  69. Litsky F. Collegiate wrestling deaths raise fears about training. The New York Times. December 19, 1997. Available at: http://www.nytimes.com/1997/12/19/sports/wrestling-collegiate-wrestling-deaths-raise-fears-about-training.html.
  70. The Associated Press. Creatine ruled out in athletes' deaths. The New York Times. May 2, 1998. Available at: http://www.nytimes.com/1998/05/02/sports/plus-college-wrestling-creatine-ruled-out-in-athletes-deaths.html.
  71. Creatine in the dock. Men's Fitness Magazine (Australia). September 2013. Available at: http://www.mensfitnessmagazine.com.au/2013/09/creatine-in-the-dock/.
  72. Galvan E, Walker Dk, Simbo SY, et al. Acute and chronic safety and efficacy of dose dependent creatine nitrate supplementation and exercise performance. J Int Soc Sports Nutr. 2016 Mar 31;13:12. PubMed
  73. Deminice R, Rosa FT, Pfrimer K, Ferrioli E, Jorao AA, Freitas E. Creatine supplementation increases total body water in soccer players: a deuterium oxide dilution study. Int J Sports Med. 2016 Feb;37(2):149-53. PubMed
  74. Wilkinson TJ, Lemmy AB, Jones AG, et al. Can creatine supplementation improve body composition and objective physical function in Rheumatoid Arthritis patients? A randomized controlled trial. Arthritis Care Res (Hoboken). 2016 Jun;68(6):729-37. PubMed
  75. Kreider RB, Kalman DS, Antonio J, et al. International Society of Sports Nutrition position stand: safety and efficacy of creating supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr. 2017;14:18.
  76. de Guingand DL, Palmer KR, Snow RJ, Davies-Tuck ML, Ellery SJ. Risk of adverse outcomes in females taking oral creatine monohydrate: a systematic review and meta-analysis. Nutrients. 2020;12(6):E1780. PubMed
  77. Almeida D, Colombini A, Machado M. Creatine supplementation improves performance, but is it safe? Double-blind placebo-controlled study. J Sports Med Phys Fitness. 2020;60(7):1034-9. PubMed
  78. Mills S, Candow DG, Forbes SC, Neary JP, Ormsbee MJ, Antonio J. Effects of creatine supplementation during resistance training sessions in physically active young adults. Nutrients. 2020;12(6):1880. PubMed
  79. Whinton AK, Donahoe K, Gao R, et al. Repeated application of a novel creatine cream improves muscular peak and average power in male subjects. J Strength Cond Res. 2020;34(9):2482-2491. PubMed
  80. Dover S, Stephens S, Schneiderman JE, et al. The effect of creatine supplementation on muscle function in childhood myositis: A randomized, double-blind, placebo-controlled feasibility study. J Rheumatol. 2020:jrheum.191375. PubMed
  81. Chilibeck PD, Candow DG, Landeryou T, Kaviani M, Paus-Jenssen L. Effects of creatine and resistance training on bone health in postmenopausal women. Med Sci Sports Exerc. 2015;47(8):1587-95. PubMed
  82. Forbes SC, Candow DG, Ostojic SM, Roberts MD, Chilibeck PD. Meta-analysis examining the importance of creatine ingestion strategies on lean tissue mass and strength in older adults. Nutrients 2021;13(6):1912. PubMed
  83. Silva C, Fung AWS, Masson V, et al. Vitamin D toxicity from an unusual and unexpected source: a report of 2 cases. Horm Res Paediatr 2022. PubMed
  84. Delpino FM, Figueiredo LM, Forbes SC, Candow DG, Santos HO. Influence of age, sex, and type of exercise on the efficacy of creatine supplementation on lean body mass: A systematic review and meta-analysis of randomized clinical trials. Nutrition 2022;103- PubMed
  85. Todorovic N, Korovljev D, Stajer V, Jorga J, Ostojic SM. Creatine consumption and liver disease manifestations in individuals aged 12?years and over. Food Sci Nutr 2022;11(2):1134-1141. PubMed
  86. Robles EL, Pache KM, Gluck JS. Acute compartment syndrome of the leg caused by cocaine use, creatine supplementation and vigorous exercise. J Surg Case Rep 2022;2022(11):rjac502. PubMed

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