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

Guarana 6000 mg Ingredients & Drug Interactions

by NusaPure

Guarana 6000 mg label
See full label image
Capsule Category: 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 Guarana 6000 mg 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

Guarana 6000 mg is a dietary supplement by NusaPure with 1 active ingredient. Its ingredients are commonly taken for energy and alertness, reducing fatigue, weight loss support.Based on those ingredients, 655 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Guarana. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Guarana 6000 mg by NusaPure

Ask about any prescription or over-the-counter medication and we check it for interactions with Guarana 6000 mg by NusaPure — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of Guarana 6000 mg by NusaPure

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 6, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains one active ingredient: guarana, a natural extract from an Amazonian plant that's used as a stimulant. Guarana's effects come primarily from its high caffeine content.

The capsules also contain inactive ingredients — cellulose, silica, and rice flour — which help form and stabilize the supplement.

Does it work?

Couldn't assess
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
Not assessable

This is a single-ingredient Guarana product and its label doesn't state a use — see Guarana's own graded uses on its monograph.

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.

The evidence we hold for guarana doesn't establish that it works for any of its claimed uses — cancer-related appetite loss, anxiety, athletic performance, or cancer-related fatigue all have insufficient reliable evidence to rate. If you're thinking about guarana for one of these reasons, talk with your doctor or pharmacist about whether the research supports it and what alternatives might be better studied.

The evidence, ingredient by ingredient Guarana

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 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Guarana is generally well tolerated when used in small amounts, but because it's high in caffeine, overuse can cause problems. The most common side effects are stomach burning and nausea.

Caffeine can also cause dizziness, insomnia (especially in children), nervousness, restlessness, tremors, headache, anxiety, and agitation. In rare cases, sensitive individuals may have an allergic reaction.

The safety data advises against guarana during pregnancy because of its high caffeine content. Caffeine passes into breast milk, so it's best avoided or limited while breastfeeding.

If you're pregnant or nursing, talk with your doctor or pharmacist before taking this product.

Side effects, ingredient by ingredient Guarana

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 1 matched ingredient can interact with medications — Guarana.
  • 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 taking guarana, check with your doctor or pharmacist if you take ephedrine or ephedrine-containing products (Major risk of serious stimulant side effects). Also double-check if you're on seizure medications like valproate, felbamate, or carbamazepine; the antipsychotic clozapine; the blood vessel dilator dipyridamole; disulfiram for alcohol dependence; fluvoxamine for depression; or any other stimulant medications.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no assessable stated purpose. Major medication interactions have been identified, and safety information is well characterized.

Guarana is a caffeine-heavy supplement with a major interaction risk if you take ephedrine and moderate concerns with seizure meds, antipsychotics, and certain antidepressants. The evidence doesn't support its use for the conditions it's marketed for.

If you're considering it, check your medications with your doctor or pharmacist first — especially if you have heart or seizure conditions, or take psychiatric medications.

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

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Mar 25, 2021.

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 Guarana 6000 mg, straight from the product label.

Brand NusaPure
Barcode (UPC) X001XFRVQN
Net contents 200 Veg Cap(s)
Market status On market
Date entered into DSLD Mar 25, 2021
DSLD ID 246554
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Dairy Free, Sugar Free
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 Guarana 6000 mg by NusaPure, 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 Veggie Capsule(s)
Maximum serving Sizes:
2 Veggie Capsule(s)
Servings per container
100
UPC/BARCODE
X001XFRVQN
IngredientAmount% DV
Guarana300 mg--

Other ingredients: Cellulose, Silica, Rice Flour

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

Directions: Take two (2) capsules daily, preferably with meal.

Precautions

Warning: For adults only.

Consult physician if pregnant/nursing, taking medication, or have a medical condition.

Do not eat freshness packet. Do not use if safety seal is damaged or missing.

Keep out of reach of children.

Allergen Information: Contains no artificial coloring, artificial flavors, yeast, corn starch, milk or milk derivatives, lactose, salt, sodium, soy, sugar, gluten, egg, wheat, fish, shellfish or tree nut ingredients. Produced in a GMP facility that processes other ingredients containing these allergens.

Storage

Store in a cool, dry place.

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.

Seals/Symbols

Premium Quality Assembled in USA Gluten Free FDA Registered Facility

Manufactured in a cGMP Inspected Facility

Formulation

GMO Free Made with non-GMO Ingredients Gluten Free FDA Registered Facility

Assembled in USA Natural Supports energy levels Supports positive mood Supports mental performance Max Strength

Allergen Information: Contains no artificial coloring, artificial flavors, yeast, corn starch, milk or milk derivatives, lactose, salt, sodium, soy, sugar, gluten, egg, wheat, fish, shellfish or tree nut ingredients.

Natural color variation may occur in this product.

FDA Statement of Identity

Dietary Supplement

Formula

Guarana 6000 mg equivalent per serving

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

See for yourself

Guarana 6000 mg by NusaPure label

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

Guarana 6000 mg 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 Guarana 6000 mg by NusaPure

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size2 Veggie Capsule(s) Dosage formCapsule Servings per container100 Amounts shown are per serving.

Guarana

Interacts with
655 drugs
300 mg per serving Form: Caffeine

Guarana is an Amazonian seed that is naturally high in caffeine, which explains most of its stimulant and energy effects. While it may give a short-te...

Guarana monograph & interactions

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

Interaction report

Guarana 6000 mg by NusaPure Drug Interactions

Want to check YOUR meds against Guarana 6000 mg?

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 462 Moderate 185 Minor

Ingredients driving the most interactions

Guarana 655

Individual Drug Interactions

The ingredients in Guarana 6000 mg interact with 655 drugs. Click any drug to see the details.

1 of the 1 ingredient in Guarana 6000 mg interact with drugs. Each result below shows which ingredient is responsible. Guarana

Each ingredient & the kinds of drugs it affects

For each ingredient in Guarana 6000 mg 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.

Guarana41 drug types · 655 drugs

Ephedrine

Theoretically, concomitant use might increase the risk for stimulant adverse effects.
Guarana contains caffeine. 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, guarana might decrease the vasodilatory effects of adenosine and interfere with its use prior to stress testing.
Guarana contains caffeine. Caffeine is a competitive inhibitor of adenosine at the cellular level. However, 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, guarana may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
In vitro and animal research suggests that guarana extract can inhibit platelet aggregation. This effect may be due to the caffeine in guarana, which is also reported to have antiplatelet activity. This interaction has not been reported in humans.

Likelihood Possible Evidence D
Beta-Adrenergic Agonists

Theoretically, concomitant use might increase the clinical effects of beta-adrenergic agonists.
Guarana contains caffeine. Theoretically, concomitant use of large amounts of caffeine might increase cardiac inotropic effects of beta-agonists.

Likelihood Probable Evidence D
Carbamazepine (Tegretol)

Theoretically, guarana 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 given to animals 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 two-fold in healthy individuals.

Likelihood Possible Evidence D
Cimetidine (Tagamet)

Theoretically, concomitant use might increase the effects and adverse effects of caffeine in guarana.
Guarana contains caffeine. Cimetidine decreases the rate of caffeine clearance by 31% to 42%.

Likelihood Likely Evidence B
Clozapine (Clozaril)

Theoretically, guarana might increase the levels and adverse effects of clozapine and acutely exacerbate psychotic symptoms.
Guarana contains caffeine. Caffeine can 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). Researchers speculate that caffeine might inhibit CYP1A2. However, there is no reliable evidence that caffeine affects CYP1A2. There is also speculation that genetic factors might make some patients more sensitive to the interaction between clozapine and caffeine.

Likelihood Possible Evidence B
Dipyridamole (Persantine)

Theoretically, guarana might decrease the vasodilatory effects of dipyridamole and interfere with its use prior to stress testing.
Guarana contains caffeine. Caffeine might inhibit 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 than adenosine-induced stress testing.

Likelihood Probable Evidence B
Disulfiram (Antabuse)

Theoretically, disulfiram might increase the risk of adverse effects from caffeine.
In human research, disulfiram decreases the clearance and increases the half-life of caffeine.

Likelihood Probable Evidence D
Diuretic Drugs

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

Likelihood Possible Evidence D
Estrogens

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

Likelihood Probable Evidence B
Ethosuximide (Zarontin)

Theoretically, guarana might reduce the effects of ethosuximide and increase the risk for convulsions.
Guarana contains caffeine. Animal research shows that caffeine 92.4 mg/kg can decrease the anticonvulsant activity of ethosuximide. This effect has not been observed in humans.

Likelihood Possible Evidence D
Felbamate (Felbatol)

Theoretically, guarana might reduce the effects of felbamate and increase the risk for convulsions.
Guarana contains caffeine. Animal research shows that a high dose of caffeine 161.7 mg/kg can decreases the anticonvulsant activity of felbamate. This effect has not been observed in humans.

Likelihood Possible Evidence D
Flutamide (Eulexin)

Theoretically, guarana might increase the levels and adverse effects of flutamide.
Guarana contains caffeine. In vitro evidence shows 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.
Guarana contains caffeine. Fluvoxamine reduces caffeine metabolism.

Likelihood Probable Evidence D
Lithium

Theoretically, abrupt guarana withdrawal might increase the levels and adverse effects of lithium.
Guarana contains caffeine. Theoretically, abrupt caffeine withdrawal might increase serum lithium levels. There are two case reports of lithium tremor that worsened upon abrupt coffee withdrawal.

Likelihood Probable Evidence D
Monoamine Oxidase Inhibitors (Maois)

Theoretically, concomitant use might increase the risk of a hypertensive crisis.
Guarana contains caffeine. Caffeine has been shown to inhibit 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.
Guarana contains caffeine. 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 D
Pentobarbital (Nembutal)

Theoretically, guarana might decrease the effects of pentobarbital.
Guarana contains caffeine. In vivo evidence suggests that caffeine can negate the hypnotic effects of pentobarbital in humans. However, animal research suggests that guarana does not alter the hypnotic effect of pentobarbital.

Likelihood Possible Evidence B
Phenobarbital (Luminal)

Theoretically, guarana might reduce the effects of phenobarbital and increase the risk for convulsions.
Guarana contains caffeine. Animal research shows that caffeine can decrease the anticonvulsant activity of phenobarbital. 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.
Guarana contains 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, guarana might reduce the effects of phenytoin and increase the risk for convulsions.
Guarana contains caffeine. Animal research shows 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, guarana might increase the levels and clinical effects of pioglitazone.
Guarana contains caffeine. 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
Riluzole (Rilutek)

Theoretically, concomitant use might increase the levels and adverse effects of both caffeine and riluzole.
Guarana contains caffeine. 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
Stimulant Drugs

Theoretically, concomitant use might increase stimulant adverse effects.
Guarana contains caffeine. Due to the central nervous system (CNS) stimulant effects of caffeine, concomitant use with stimulant drugs can increase the risk of adverse effects.

Likelihood Possible Evidence D
Guarana full monograph & all 41 interactions
The maker

Brand information

Manufacturer and brand details for Guarana 6000 mg, from the product label.

NusaPure

See all NusaPure products
Name
Gmax Central LLC
Street Address
4700 Millenia Boulevard, Suite 175 PMB 92909
City
Orlando
State
FL
ZipCode
32839
Pharmacist Counseling Corner

Guarana 6000 mg by NusaPure: Common Questions

Does Guarana 6000 mg by NusaPure interact with any medications?
Yes. Based on its ingredients, Guarana 6000 mg 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?
Guarana 6000 mg contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism 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.
What exactly is guarana?
Guarana is an extract from a plant native to the Amazon rainforest. It's used as a stimulant because it's naturally high in caffeine. This 6000 mg capsule delivers a concentrated dose of that caffeine.
Can I take guarana while pregnant?
The safety data advises against it. Guarana is high in caffeine, which is not recommended during pregnancy. Talk with your doctor or pharmacist before taking it if you're pregnant or planning to become pregnant.
Is guarana safe while breastfeeding?
Caffeine passes into breast milk, so it's best avoided or limited while breastfeeding. If you're nursing and considering guarana, talk with your doctor or pharmacist first.
What are the most common side effects?
Stomach burning and nausea are the most commonly reported. Because of the high caffeine dose, you might also experience dizziness, insomnia, nervousness, restlessness, tremors, headache, or anxiety.
Does guarana actually work for energy or athletic performance?
The evidence we hold doesn't establish that guarana works for athletic performance, energy, anxiety, or cancer-related fatigue. If you're thinking about it for one of these reasons, ask your doctor or pharmacist about better-studied alternatives.
What's in the capsule besides guarana?
The inactive ingredients are cellulose, silica, and rice flour — they help form and stabilize the capsule. These are standard excipients and don't have active effects.

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.

Guarana 6000 mg label
Go deeper

The Full Monographs Behind Guarana 6000 mg’s Ingredients

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

Herb & supplement monograph

Guarana

Interacts with 655 drugs

Guarana is an Amazonian seed that is naturally high in caffeine, which explains most of its stimulant and energy effects. While it may give a short-term boost in alertness and reduce fatigue...

Read the full Guarana monograph →
Sources

Sources & How We Checked

Guarana 6000 mg'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 114 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.

Guarana 114 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. Boozer CN, Nasser JA, Heymsfield SB, et al. An herbal supplement containing Ma Huang-Guarana for weight loss: a randomized, double-blind trial. Int J Obes Relat Metab Disord 2001;25:316-24. PubMed
  21. Briggs GB, Freeman RK, Yaffe SJ. Drugs in Pregnancy and Lactation. 5th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 1998.
  22. 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
  23. 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
  24. 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
  25. 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
  26. American Academy of Pediatrics. The transfer of drugs and other chemicals into human milk. Pediatrics 2001;108:776-89. PubMed
  27. Sinclair CJ, Geiger JD. Caffeine use in sports. A pharmacological review. J Sports Med Phys Fitness 2000;40:71-9.
  28. 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
  29. Ali M, Afzal M. A potent inhibitor of thrombin stimulated platelet thromboxane formation from unprocessed tea. Prostaglandins Leukot Med 1987;27:9-13. PubMed
  30. 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
  31. 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
  32. Haller CA, Jacob P 3rd, Benowitz NL. Pharmacology of ephedra alkaloids and caffeine after single-dose dietary supplement use. Clin Pharmacol Ther 2002;71:421-32. PubMed
  33. 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
  34. 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
  35. 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
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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.

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