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

Grape Seed Xtra 50 mg Ingredients & Drug Interactions

by Sundown Naturals

Grape Seed Xtra 50 mg label
See full label image
Capsule Category: Botanical With Nutrients
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 Grape Seed Xtra 50 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

Grape Seed Xtra 50 mg is a dietary supplement by Sundown Naturals with 5 active ingredients. Its ingredients are commonly taken for antioxidant support, weight loss, heart health.Based on those ingredients, 1,558 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Green Tea, Citrus Bioflavonoids, Grape Seed Extract. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Grape Seed Xtra 50 mg by Sundown Naturals

Ask about any prescription or over-the-counter medication and we check it for interactions with Grape Seed Xtra 50 mg by Sundown Naturals — 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 Grape Seed Xtra 50 mg by Sundown Naturals

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

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 2 of its 5 active ingredients.
  • “Xtra Premium Blend (Combination)” is a proprietary blend — the label gives one combined amount (130 mg) without saying how much of each component you get.
  • “Grape Seed Extract” is listed as a grouped ingredient — the label gives one combined amount (50 mg) without saying how much of each component you get.

This product contains 5 active ingredients: green tea, citrus bioflavonoids (a type of plant compound), a standardized polyphenol blend, bilberry, and selenium. Green tea and bilberry are plant extracts rich in compounds called flavonoids; selenium is a mineral.

These are combined in what the label calls an "Xtra Premium Blend." The capsule itself is made from gelatin, and the remaining inactive ingredients include rice flour, silica, vegetable magnesium stearate, and beet root powder.

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

This product doesn't appear to be marketed for a specific use, so we graded its ingredients' overall clinical evidence instead.

Strong

Strong clinical evidence supports its ingredients for:

Why this rating?
  • The label markets general wellness (“antioxidant health support”), not a specific health condition, so there is no single claim to grade against clinical-evidence data.
  • Since the label doesn't commit to one use, we graded the ingredients' overall clinical evidence instead.
  • On file: Human papillomavirus (HPV) — rated "Likely Effective" (Green Tea) (Natural Medicines).
  • On file: Selenium deficiency — rated "Likely Effective" (Selenium) (Natural Medicines).
  • On file: Cardiovascular disease (CVD) — rated "Possibly Effective" (Green Tea) (Natural Medicines).
  • On file: Endometrial cancer — rated "Possibly Effective" (Green Tea) (Natural Medicines).
  • On file: Hyperlipidemia — rated "Possibly Effective" (Green Tea) (Natural Medicines).

The evidence for effectiveness varies by ingredient and what you're taking it for. Green tea is likely effective for human papillomavirus (HPV) and possibly effective for lowering cholesterol (hyperlipidemia) and reducing ovarian cancer risk, though the strength of that last finding is limited.

Bilberry and citrus bioflavonoids do not have strong evidence behind them for their commonly promoted uses—the data we hold rates bilberry's claimed benefit for night vision as possibly ineffective, and rates most other claimed uses (cognitive decline, age-related macular degeneration, atherosclerosis, cholesterol) as having insufficient reliable evidence. For selenium, the strongest evidence supports its use in treating selenium deficiency itself; it's possibly effective for Kashin-Beck disease (a joint condition), pre-eclampsia, and autoimmune thyroiditis, but possibly ineffective for high cholesterol.

The evidence, ingredient by ingredient Green Tea Quercetin Bilberry Selenium Grape

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 4 of the 4 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 4 of 4.
  • General safety write-ups exist for 4 of 4.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Green tea is generally well tolerated when consumed as a beverage or extract in moderate amounts for up to 12 months, though concentrated high-dose extracts have rarely been linked to liver injury. The most common side effects are gastrointestinal—bloating, constipation, diarrhea, nausea, and indigestion—especially at higher doses.

A rare but serious allergic reaction (anaphylaxis) to green tea proteins has been reported. Bilberry fruit is generally well tolerated as food, though supplement safety is less well studied; common side effects include dark-colored stools, flatulence, and mild gastrointestinal discomfort.

Citrus bioflavonoids at typical food levels are well tolerated, but high-dose supplement safety is not well studied. Selenium is safe in the recommended amounts but can become toxic in excess; doses above the daily upper limit of 400 mcg can cause hair loss, nail problems, fatigue, nausea, and in rare cases serious multi-organ damage.

For pregnancy: green tea is rated possibly safe at moderate intake but possibly unsafe at high doses; citrus bioflavonoids and bilberry lack sufficient safety data (avoid supplemental doses); selenium is rated possibly safe in pregnancy and possibly unsafe at high doses. For breastfeeding: green tea and selenium are rated possibly safe if kept moderate, but citrus bioflavonoids and bilberry lack sufficient safety data—avoid supplemental doses.

Side effects, ingredient by ingredient Green Tea Quercetin Bilberry Selenium Grape

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?
  • 4 of the 4 matched ingredients can interact with medications — Bilberry, Quercetin, Green Tea, Selenium.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; immunosuppressants / transplant drugs; diabetes medications; lithium.
  • For scale: 1,547 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 this product, check with your doctor or pharmacist if you take: blood thinners or antiplatelet drugs (Major concern with green tea and nadolol; Moderate with bilberry and selenium), seizure medications (Moderate concern with green tea), beta blockers like nadolol, statins like atorvastatin or pravastatin, diabetes medications, ephedrine, cyclosporine, immunosuppressants, barbiturate sedatives, or quinolone antibiotics. No interactions are documented in our data for the ingredient listed as "standardized to contain polyphenols."

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFormula with limited ingredient disclosure with strong clinical evidence behind its ingredients' uses. Major medication interactions have been identified, and safety information is well characterized.

This product combines green tea, bilberry, citrus bioflavonoids, selenium, and a polyphenol blend. If you take any medications—especially blood thinners, seizure medications, beta blockers, statins, diabetes drugs, or immunosuppressants—you need to check your exact prescriptions against the interaction tool on this page before starting.

Even if you have no major interactions, talk it over with your doctor or pharmacist, especially if you're pregnant, breastfeeding, or taking high-dose supplements.

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

Assessment coverage: 4 of 5 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Mar 25, 2014.

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

At a glance

General information

Key facts about Grape Seed Xtra 50 mg, straight from the product label.

Brand Sundown Naturals
Barcode (UPC) 030768012076
Net contents 60 Capsule(s)
Market status On market
Date entered into DSLD Mar 25, 2014
DSLD ID 31652
Product type Botanical With Nutrients
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 Grape Seed Xtra 50 mg by Sundown Naturals, 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:
1 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
UPC/BARCODE
030768012076
IngredientAmount% DV
Green Tea0 NP--
Citrus Bioflavonoids0 NP--
standardized to contain polyphenols22.5 mg--
Xtra Premium Blend (Combination)130 mg--
Bilberry0 NP--
Selenium15 mcg21%
Grape Seed Extract50 mg--

Other ingredients: Rice Flour, Gelatin, Silica, Vegetable Magnesium Stearate, Beet root powder

Tap any ingredient to jump to its full detail below.

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

As a reminder, discuss the supplements and medications you take with your health care providers.

Standardized

Helps Promote Antioxidant Health*

Our Product helps fight cell-damaging free radicals in the body.*

Precautions

KEEP OUT OF REACH OF CHILDREN.

WARNING: If you are pregnant, nursing or taking any medications, consult your doctor before use.

Discontinue use and consult your doctor if any adverse reactions occur.

TAMPER RESISTANT: DO NOT USE IF SEAL UNDER CAP IS BROKEN OR MISSING.

Avoid this product if you are allergic to yeast.

Formulation

No Artificial Flavor or Sweetener, No Preservatives, No Sugar, No Milk, No Lactose, No Soy, No Gluten, No Wheat, No Fish. Sodium Free.

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

PLEASE RECYCLE

GUARANTEED LABORATORY TESTED QUALITY

General

Prod. No. 44765 09F B11860 AAB

Suggested/Recommended/Usage/Directions

DIRECTIONS: FOR ADULTS, TAKE ONE (1) CAPSULE TWO TIMES DAILY, PREFERABLY WITH MEALS.

Storage

STORE AT ROOM TEMPERATURE AND AVOID EXCESSIVE HEAT.

Brand IP Statement(s)

2012

FDA Statement of Identity

HERBAL SUPPLEMENT

Formula

Smart Facts This special blend includes Green Tea, Citrus Bioflavonoids, Bilberry and Selenium, all intended for your overall well-being.*

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

See for yourself

Grape Seed Xtra 50 mg by Sundown Naturals label

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

Grape Seed Xtra 50 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 Grape Seed Xtra 50 mg by Sundown Naturals

These are the 5 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule 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.

Xtra Premium Blend (Combination)

130 mg per serving

Selenium

Interacts with
321 drugs
15 mcg per serving Form: Selenium Proteinate, Selenium Yeast

Selenium is an essential trace mineral your body needs in small amounts for thyroid function, antioxidant defense, and immune health. Most people who...

Selenium monograph & interactions

Grape Seed Extract

Interacts with
910 drugs
50 mg per serving

Grapes and grape products like grape seed extract contain antioxidant compounds such as resveratrol and proanthocyanidins that may support heart and b...

Grape Seed Extract monograph & interactions
  • › Standardized to contain polyphenols

Other (inactive) ingredients: Rice Flour, Gelatin, Silica, Vegetable Magnesium Stearate, Beet root powder. These complete the product’s ingredient list but are not active constituents.

Interaction report

Grape Seed Xtra 50 mg by Sundown Naturals Drug Interactions

Want to check YOUR meds against Grape Seed Xtra 50 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
1,558Drugs
13 Major 1,534 Moderate 11 Minor

Ingredients driving the most interactions

Green Tea 1,293
Citrus Bioflavonoids 1,169
Grape Seed Extract 910
Selenium 321
Bilberry 275

Individual Drug Interactions

The ingredients in Grape Seed Xtra 50 mg interact with 1,558 drugs. Click any drug to see the details.

5 of the 5 ingredients in Grape Seed Xtra 50 mg interact with drugs. Each result below shows which ingredient is responsible. Green Tea Citrus Bioflavonoids Grape Seed Extract Selenium Bilberry

Each ingredient & the kinds of drugs it affects

For each ingredient in Grape Seed Xtra 50 mg with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.

Green Tea58 drug types · 1,293 drugs

Atorvastatin (Lipitor)

Green tea extract seems to reduce the levels and clinical effects of atorvastatin.
In healthy humans, taking green tea extract 300 mg or 600 mg along with atorvastatin reduces plasma levels of atorvastatin by approximately 24%. The elimination of atorvastatin is not affected. Atorvastatin is a substrate of organic anion-transporting polypeptides (OATPs). Research shows that two of the major catechins found in green tea, epicatechin gallate (ECG) and epigallocatechin gallate (EGCG), inhibit OATPs. Some OATPs are expressed in the small intestine and are responsible for the uptake of drugs and other compounds, which may have resulted in reduced plasma levels of atorvastatin. It is not clear if drinking green tea alters the absorption of atorvastatin.

Likelihood Likely Evidence B
Ephedrine

Theoretically, concomitant use might increase the risk for stimulant adverse effects.
Green tea contains caffeine. 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
Nadolol (Corgard)

Green tea seems to reduce the levels and clinical effects of nadolol.
Preliminary clinical research shows that green tea consumption reduces plasma concentrations of nadolol. Compared to a control group, both peak levels and total drug exposure (AUC) of nadolol were reduced by approximately 85% in subjects who drank green tea daily for two weeks. Drinking green tea with nadolol also significantly reduced nadolol's systolic blood pressure lowering effect. Other clinical research shows that a single dose of green tea can affect plasma nadolol levels for at least one hour. Green tea catechins have been shown to inhibit organic anion transporting polypeptides (OATP), one of which, OATP1A2, is involved in the uptake of nadolol in the intestine The interaction is thought to be due primarily to the epigallocatechin gallate (EGCG) content of green tea.

Likelihood Likely Evidence B
5-Fluorouracil

Theoretically, high doses of green tea might increase the effects and side effects of 5-fluorouracil.
Animal research shows that taking green tea in amounts equivalent to about 6 cups daily in humans for 4 weeks prior to receiving a single injection of 5-fluorouracil increases the maximum plasma levels of 5-fluorouracil by about 2.5-fold and the area under the curve by 425%.

Likelihood Possible Evidence D
Adenosine (Adenocard)

Theoretically, green tea might decrease the vasodilatory effects of adenosine and interfere with its use prior to stress testing.
Green tea contains caffeine. Caffeine is a competitive inhibitor of adenosine at the cellular level. However, caffeine doesn't 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, green tea may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Conflicting reports exist regarding the effect of green tea on bleeding risk when used with anticoagulant or antiplatelet drugs; however, most evidence suggests that drinking green tea in moderate amounts is unlikely to cause a significant interaction. Green tea contains small amounts of vitamin K, approximately 7 mcg per cup. Some case reports have associated the antagonism of warfarin with the vitamin K content of green tea. However, these reports are rare, and very large doses of green tea (about 8-16 cups daily) appear to be needed to cause these effects. Furthermore, the catechins and caffeine in green tea are reported to have antiplatelet activity.

Likelihood Unlikely Evidence D
Beta-Adrenergic Agonists

Green tea contains caffeine. Theoretically, concomitant use of large amounts of caffeine might increase cardiac inotropic effects of beta-agonists.

Likelihood Probable Evidence D
Bortezomib (Velcade)

Theoretically, green tea might interfere with the effects of bortezomib.
In vitro research shows that green tea polyphenols, such as epigallocatechin gallate (EGCG), interact with bortezomib and block its proteasome inhibitory action. This prevents the induction of cell death in multiple myeloma or glioblastoma cancer cell lines. Advise patients taking bortezomib, not to take green tea.

Likelihood Possible Evidence D
Carbamazepine (Tegretol)

Theoretically, green tea might reduce the effects of carbamazepine and increase the risk for convulsions.
Green tea contains caffeine. 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
Celiprolol (Celicard)

Theoretically, green tea might reduce the levels and clinical effects of celiprolol.
In a small human study, taking green tea daily for 4 days appears to decrease blood and urine levels of celiprolol by at least 98%. This interaction is possibly due to the inhibition of organic anion transporting polypeptide (OATP). Green tea catechins have been shown to inhibit organic anion transporting polypeptides (OATP), one of which, OATP1A2, is found in the intestine The interaction is thought to be due primarily to the epigallocatechin gallate (EGCG) content of green tea.

Likelihood Possible Evidence D
Cimetidine (Tagamet)

Theoretically, concomitant use might increase the effects and adverse effects of caffeine in green tea.
Green tea contains caffeine. Cimetidine can reduce caffeine clearance by 31% to 42%.

Likelihood Likely Evidence B
Clozapine (Clozaril)

Theoretically, green tea might increase the levels and adverse effects of clozapine and acutely exacerbate psychotic symptoms.
Animal research suggests that, although green tea extract does not affect the elimination of clozapine, it delays the time to reach peak concentration and reduces the peak plasma levels. Also, concomitant administration of green tea and clozapine might theoretically cause acute exacerbation of psychotic symptoms due to the caffeine in green tea. Caffeine can increase the effects and toxicity of clozapine. Caffeine doses of 400-1000 mg daily 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 be more sensitive to the interaction between clozapine and caffeine.

Likelihood Possible Evidence B
Contraceptive Drugs

Theoretically, concomitant use might increase the effects and adverse effects of caffeine found in green tea.
Green tea contains caffeine. Oral contraceptives can decrease caffeine clearance by 40% to 65%.

Likelihood Probable Evidence B
Cytochrome P450 1A2 (Cyp1A2) Inhibitors

Theoretically, concomitant use might increase the levels and adverse effects of caffeine.
Green tea contains caffeine. Caffeine is metabolized by cytochrome P450 1A2 (CYP1A2),. Theoretically, drugs that inhibit CYP1A2 may decrease the clearance rate of caffeine from green tea and increase caffeine levels.

Likelihood Possible Evidence D
Dipyridamole (Persantine)

Theoretically, green tea might decrease the vasodilatory effects of dipyridamole and interfere with its use prior to stress testing.
Green tea 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 (Persantine) 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 B
Diuretic Drugs

Theoretically, using green tea with diuretic drugs might increase the risk of hypokalemia.
Green tea contains caffeine. In excessive amounts, caffeine 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.
Green tea contains caffeine. Estrogen inhibits caffeine metabolism.

Likelihood Probable Evidence B
Ethosuximide (Zarontin)

Theoretically, green tea might reduce the effects of ethosuximide and increase the risk for convulsions.
Green tea contains caffeine. 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, green tea might reduce the effects of felbamate and increase the risk for convulsions.
Green tea contains caffeine. 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
Fexofenadine (Allegra)

Green tea can decrease blood levels of fexofenadine.
Clinical research shows that green tea can significantly decrease blood levels and excretion of fexofenadine. Taking green tea extract with a dose of fexofenadine decreased bioavailability of fexofenadine by about 30%. In vitro, green tea inhibits the cellular accumulation of fexofenadine by inhibiting the organic anion transporting polypeptide (OATP) drug transporter. Research shows that two of the major catechins found in green tea, epicatechin gallate (ECG) and epigallocatechin gallate (EGCG), inhibit OATPs, specifically OATP1A2, OATP1B1, and OATP2B1. In addition, green tea has been shown to reduce the absorption of some drugs that are OATP substrates.

Likelihood Probable Evidence B
Flutamide (Eulexin)

Theoretically, green tea might increase the levels and adverse effects of flutamide.
Green tea contains caffeine. In vitro evidence suggests that caffeine can inhibit the metabolism of flutamide. Theoretically, concomitant use of caffeine and flutamide might increase serum concentrations of flutamide and increase the risk adverse effects.

Likelihood Possible Evidence D
Fluvoxamine (Luvox)

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

Likelihood Probable Evidence D
Hepatotoxic Drugs

Theoretically, concomitant use might have additive adverse hepatotoxic effects.
Green tea extract supplements have been linked to several cases of hepatotoxicity and might have additive hepatotoxic effects with other drugs..

Likelihood Unlikely Evidence D
Imatinib (Gleevec)

Theoretically, green tea might reduce the levels and clinical effects of imatinib.
In animal research, a single dose of green tea extract reduces the area under the curve (AUC) of imatinib by up to approximately 64% and its main metabolite N-desmethyl imatinib by up to approximately 81%. This interaction has not been shown in humans. The mechanism of action is unclear but may involve multiple pathways.

Likelihood Possible Evidence D
Green Tea full monograph & all 58 interactions

Citrus Bioflavonoids21 drug types · 1,169 drugs

Antidiabetes Drugs

Theoretically, concomitant use of quercetin and antidiabetes drugs might increase the risk of hypoglycemia.

Clinical research suggests that a combination of quercetin, myricetin, and chlorogenic acid reduce levels of fasting glucose in patients with type 2 diabetes, including those already taking antidiabetes agents. The effect of quercetin alone is unknown.

Likelihood Possible Evidence B
Antihypertensive Drugs

Theoretically, taking quercetin with antihypertensive drugs might increase the risk of hypotension.

Quercetin can modestly decrease blood pressure in people with mild hypertension. Theoretically, it might have additive blood pressure lowering effects when used with antihypertensive drugs.

Likelihood Possible Evidence B
Cyclosporine (Neoral, Sandimmune)

Theoretically, concomitant use might increase the levels and adverse effects of cyclosporine.

A small study in healthy volunteers shows that pretreatment with quercetin increases plasma levels and prolongs the half-life of a single dose of cyclosporine, possibly due to inhibition of p-glycoprotein or cytochrome P450 3A4 (CYP3A4), which metabolizes cyclosporin.

Likelihood Possible Evidence B
Cytochrome P450 2C8 (Cyp2C8) Substrates

Theoretically, concomitant use might increase the levels and adverse effects of CYP2C8 substrates.

In vitro research shows that quercetin inhibits CYP2C8. Inhibition of paclitaxel (Taxol) metabolism via CYP2C8 has been reported in vitro. However, a small study in humans found no effect of quercetin on rosiglitazone (Avandia), which is also a CYP2C8 substrate.

Likelihood Possible Evidence D
Cytochrome P450 2C9 (Cyp2C9) Substrates

Theoretically, concomitant use might increase the levels and adverse effects of CYP2C9 substrates.

A small clinical study in healthy volunteers shows that taking quercetin 500 mg twice daily for 10 days prior to taking diclofenac, a CYP2C9 substrate, increases diclofenac plasma levels by 75% and prolongs the half-life by 32.5%. Animal research also shows that pretreatment with quercetin increases plasma levels and prolongs the half-life of losartan (Cozaar), a substrate of CYP2C9. Furthermore, laboratory research shows that quercetin inhibits CYP2C9.

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

Theoretically, concomitant use might increase the levels and adverse effects of CYP2D6 substrates.

In vitro research show that quercetin inhibits CYP2D6. This effect has not been reported in humans.

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

Theoretically, concomitant use might alter the effects and adverse effects of CYP3A4 substrates.
A small clinical study in healthy volunteers shows that pretreatment with quercetin increases plasma levels and prolongs the half-life of a single dose of cyclosporine (Neoral, Sandimmune), a substrate of CYP3A4. Animal research also shows that pretreatment with quercetin increases plasma levels and prolongs the half-life of losartan (Cozaar) and quetiapine (Seroquel), substrates of CYP3A4. Other laboratory research also shows that quercetin inhibits CYP3A4. However, one clinical study shows that quercetin can increase the metabolism of midazolam, a substrate of CYP3A4, and decrease serum concentrations of midazolam by about 24% in some healthy individuals, suggesting possible induction of CYP3A4.

Likelihood Possible Evidence D
Diclofenac (Voltaren, Others)

Theoretically, concomitant use might increase the levels and adverse effects of diclofenac.

A small clinical study in healthy volunteers shows that taking quercetin 500 mg twice daily for 10 days prior to taking diclofenac increases diclofenac plasma levels by 75% and prolongs the half-life by 32.5%. This is thought to be due to inhibition of CYP2C9 by quercetin.

Likelihood Probable Evidence B
Losartan (Cozaar)

Theoretically, concomitant use might increase the effects and adverse effects of losartan and decrease the effects of its active metabolite.

Animal research shows that pretreatment with quercetin increases plasma levels and prolongs the half-life of losartan (Cozaar) while decreasing plasma levels of losartan's active metabolite. This metabolite, which is around 10-fold more potent than losartan, is the result of cytochrome P450 (CYP) 2C9- and CYP3A4-mediated transformation of losartan. Additionally, in vitro research shows that quercetin may inhibit P-glycoprotein-mediated efflux of losartan from the intestines, resulting in increased absorption of losartan. These results suggest that concomitant use of quercetin and losartan might increase systemic exposure to losartan while also decreasing plasma concentrations of losartan's active and more potent metabolite.

Likelihood Possible Evidence D
Midazolam (Versed)

Theoretically, concomitant use might decrease the levels and effects of midazolam.

A small clinical study in healthy volunteers shows that quercetin can increase the metabolism of midazolam, with a decrease in AUC of about 24%.

Likelihood Possible Evidence B
Mitoxantrone

Theoretically, quercetin might increase the effects and adverse effects of mitoxantrone.
In vitro research shows that quercetin increases the intracellular accumulation and cytotoxicity of mitoxantrone, possibly through inhibition of breast cancer resistance protein (BCRP), of which mitoxantrone is a substrate. So far, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Organic Anion Transporter 1 (Oat1) Substrates

Theoretically, concomitant use might increase the effects and adverse effects of OAT1 substrates.

In vitro research shows that quercetin is a strong non-competitive inhibitor of OAT1, with half-maximal inhibitory concentration (IC50) values less than 10 mcM. So far, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Organic Anion Transporter 3 (Oat3) Substrates

Theoretically, concomitant use might increase the effects and adverse effects of OAT3 substrates.

In vitro research shows that quercetin is a strong non-competitive inhibitor of OAT3, with half-maximal inhibitory concentration (IC50) values as low as 0.75 mcM. So far, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Organic Anion-Transporting Polypeptide Substrates (Oatp)

Theoretically, concomitant use might increase the effects and adverse effects of OATP substrates.

In vitro evidence shows that quercetin can inhibit organic anion-transporting peptide (OATP) 1B1-mediated uptake of estrone-3-sulfate and pravastatin. Furthermore, clinical research in healthy males shows that intake of quercetin along with pravastatin increases the AUC of pravastatin by 24%, prolongs its half-life by 14%, and decreases its apparent clearance by 18%, suggesting that quercetin modestly inhibits the uptake of pravastatin in hepatic cells.

Likelihood Possible Evidence B
P-Glycoprotein Substrates

Theoretically, concomitant use might alter the effects and adverse effects of P-glycoprotein substrates.

There is preliminary evidence that quercetin inhibits the gastrointestinal P-glycoprotein efflux pump, which might increase the bioavailability and serum levels of drugs transported by the pump. A small study in healthy volunteers reported that pretreatment with quercetin increased bioavailability and plasma levels after a single dose of cyclosporine (Neoral, Sandimmune). Also, two small studies have shown that quercetin might decrease the absorption of talinolol, a substrate transported by the gastrointestinal P-glycoprotein efflux pump. However, in another small study, several days of quercetin treatment did not significantly affect the pharmacokinetics of saquinavir (Invirase). The reason for these discrepancies is not entirely clear. Until more is known, use quercetin cautiously in combination with P-glycoprotein substrates.

Likelihood Possible Evidence B
Pravastatin (Pravachol)

Theoretically, concomitant use might increase the effects and adverse effects of pravastatin.
In vitro evidence shows that quercetin can inhibit OATP 1B1-mediated uptake of pravastatin. Also, preliminary clinical research in healthy males shows that intake of quercetin along with pravastatin increases the maximum concentration of pravastatin by 24%, prolongs its half-life by 14%, and decreases its apparent clearance by 18%, suggesting that quercetin modestly inhibits the uptake of pravastatin in hepatic cells.

Likelihood Possible Evidence B
Prazosin (Minipress)

Theoretically, quercetin might increase the effects and adverse effects of prazosin.
In vitro research shows that quercetin inhibits the transcellular efflux of prazosin, possibly through inhibition of breast cancer resistance protein (BCRP), of which prazosin is a substrate. BCRP is an ATP-binding cassette efflux transporter in the intestines, kidneys, and liver. So far, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Quetiapine (Seroquel)

Theoretically, concomitant use might increase the effects and adverse effects of quetiapine.
Animal research shows that pretreatment with quercetin can increase plasma levels of quetiapine and prolong its clearance, possibly due to inhibition of cytochrome P450 3A4 (CYP3A4) by quercetin. Additionally, the brain-to-plasma ratio of quetiapine concentrations increased, possibly due to inhibition of P-glycoprotein at the blood-brain barrier. This interaction has not been reported in humans.

Likelihood Possible Evidence D
Quinolone Antibiotics

Theoretically, concomitant use might inhibit the effects of quinolone antibiotics.
In vitro, quercetin binds to the DNA gyrase site on bacteria, which may interfere with the activity of quinolone antibiotics.

Likelihood Possible Evidence B
Sulfasalazine (Azulfidine)

Theoretically, quercetin might increase the effects and adverse effects of sulfasalazine.
Animal research shows that quercetin increases the maximum serum concentration (Cmax) and area under the curve (AUC) of sulfasalazine, possibly through inhibition of breast cancer resistance protein (BCRP), of which sulfasalazine is a substrate. So far, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Theoretically, quercetin may increase the risk of bleeding if used with warfarin.
Animal and in vitro studies show that quercetin might increase serum levels of warfarin. Quercetin and warfarin have the same human serum albumin (HSA) binding site, and in vitro research shows that quercetin has stronger affinity for the HSA binding site and can theoretically displace warfarin, causing higher serum levels of warfarin. Animal research shows that taking quercetin for 2 weeks before initiating warfarin increases the maximum serum level of warfarin by 30%, the half-life by 10%, and the overall exposure by 63% when compared with control. Concomitant administration of quercetin and warfarin, without quercetin pre-treatment, also increased these measures, but to a lesser degree. Researchers theorize that inhibition of CYP3A4 by quercetin may explain these effects. So far, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Citrus Bioflavonoids full monograph & interactions

Grape Seed Extract9 drug types · 910 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, grape extracts may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
In vitro evidence suggests that grape extracts might decrease platelet aggregation.

Likelihood Possible Evidence D
Cyclosporine (Neoral, Sandimmune)

Ingesting grape juice with cyclosporine can reduce cyclosporine absorption.
A small pharmacokinetic study in healthy young adults shows that intake of purple grape juice 200 mL along with cyclosporine can decrease the absorption of cyclosporine by up to 30% when compared with water. Separate doses of grape juice and cyclosporine by at least 2 hours to avoid this interaction.

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

Theoretically, grape juice might reduce the levels of CYP1A2 substrates.
A small pharmacokinetic study in healthy adults shows that ingestion of 200 mL of grape juice decreases phenacetin plasma levels. This is thought to be due to induction of CYP1A2.

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

Theoretically, grape seed extract may increase the levels of CYP2D6 substrates.
In vitro evidence suggests that grape seed extract might inhibit CYP2D6 enzymes. However, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 2E1 (Cyp2E1) Substrates

Theoretically, grape seed extract might increase the levels of CYP2E1 substrates.
In vitro and animal research suggests that grape seed proanthocyanidin extract inhibits CYP2E1 enzymes. However, this interaction has not been reported in humans.

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

It is unclear if grape seed extract inhibits or induces CYP3A4; research is conflicting.
In vitro evidence suggests that grape seed extract might inhibit CYP3A4 enzymes. However, evidence from animal research shows that grape seed extract may induce CYP3A4 in the liver. So far, these interactions have not been reported in humans.

Likelihood Possible Evidence D
Midazolam (Versed)

Theoretically, long-term intake of grape seed extract might decrease the effects of midazolam.
Animal research shows that subchronic ingestions of grape seed extract can increase the elimination of intravenous midazolam by increasing hepatic CYP3A4 activity. Single doses of grape seed extract do not appear to affect midazolam elimination.

Likelihood Possible Evidence D
Phenacetin

Grape juice might decrease phenacetin absorption.
A small pharmacokinetic study in healthy adults shows that ingestion of 200 mL of grape juice decreases phenacetin plasma levels. This is thought to be due to induction of cytochrome P450 1A2 (CYP1A2).

Likelihood Possible Evidence B
Cytochrome P450 2C9 (Cyp2C9) Substrates

It is unclear if grape juice or grape seed extract inhibits CYP2C9; research is conflicting.
In vitro evidence shows that grape seed extract or grape juice might inhibit CYP2C9 enzymes. However, a small pharmacokinetic study in healthy adults shows that drinking 8 ounces of grape juice once does not affect the clearance of flurbiprofen, a probe-drug for CYP2C9 metabolism. The effects of continued grape juice consumption are unclear.

Likelihood Unlikely Evidence D
Grape Seed Extract full monograph & interactions

Selenium6 drug types · 321 drugs

Anticoagulant/Antiplatelet Drugs

Selenium may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Clinical research suggests that taking selenium 10 mcg/kg/day can increase bleeding times by increasing prostacyclin production, which inhibits platelet activity. Other clinical research suggests that taking selenium 75 mcg daily, in combination with ascorbic acid 600 mg, alpha-tocopherol 300 mg, and beta-carotene 27 mg, reduces platelet aggregation.

Likelihood Possible Evidence D
Barbiturates

Theoretically, selenium might prolong the sedating effects of barbiturates.
Laboratory research suggests that selenium can inhibit the hepatic metabolism of barbiturates. Selenium seems to prolong the sedative effect of pentobarbital in animal models.

Likelihood Possible Evidence D
Immunosuppressants

Theoretically, selenium supplementation may reduce the effectiveness of immunosuppressant therapy.
In vitro research and preliminary clinical evidence suggests that selenium may stimulate the immune system.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Theoretically, selenium might interfere with warfarin activity.
Animal research suggests that selenium can increase warfarin activity. Selenium might interact with warfarin by displacing it from albumin binding sites, reducing its metabolism in the liver, or by decreasing production of vitamin K-dependent clotting factors. Selenium can also prolong bleeding times in humans by increasing prostacyclin production, which inhibits platelet activity.

Likelihood Possible Evidence D
Contraceptive Drugs

Contraceptive drugs might increase levels of selenium, although the clinical significance of this effect is unclear.
Some research suggests that oral contraceptives increase serum selenium levels in women taking oral contraceptives; however, other research shows no change in selenium levels. It is suggested that an increase could be due to increased carrier proteins, indicating a redistribution of selenium rather than a change in total body selenium.

Likelihood Possible Evidence B
Niacin

Selenium might reduce the beneficial effects of niacin on high-density lipoprotein (HDL) levels.
A combination of niacin and simvastatin (Zocor) effectively raises HDL cholesterol levels in patients with coronary disease and low HDL levels. Clinical research shows that taking a combination of antioxidants (vitamin C, vitamin E, beta-carotene, and selenium) along with niacin and simvastatin (Zocor) attenuates this rise in HDL, specifically the HDL-2 and apolipoprotein A1 fractions, by more than 50% in patients with coronary disease. It is not known whether this adverse effect is due to a single antioxidant such as selenium, or to the combination. It also is not known whether it will occur in other patient populations.

Likelihood Possible Evidence A
Selenium full monograph & interactions

Bilberry4 drug types · 275 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, bilberry fruit extract might increase the risk of bleeding when taken with anticoagulant or antiplatelet drugs.
In vitro, animal, and clinical research suggest that anthocyanidin extracts from bilberry can inhibit platelet aggregation.

Likelihood Possible Evidence D
Antidiabetes Drugs

Theoretically, bilberry leaf or fruit extract may increase the risk of hypoglycemia when taken with antidiabetes drugs.
Animal research suggests that bilberry leaf extract might have blood glucose-lowering activity. Also, one small clinical trial in patients with type 2 diabetes shows that taking bilberry fruit extract 470 mg as a single dose prior to an oral glucose tolerance test lowers plasma glucose levels when compared with placebo.

Likelihood Possible Evidence D
Cytochrome P450 2E1 (Cyp2E1) Substrates

Theoretically, bilberry fruit extract might decrease levels of drugs metabolized by CYP2E1.
Animal research shows that exposure to small concentrations of bilberry extract in drinking water for around one month increased CYP2E1 activity by 31%. However, exposure over a 2-month period did not increase CYP2E1 activity. This effect has not been reported in humans.

Likelihood Possible Evidence D
Erlotinib (Tarceva)

Theoretically, bilberry fruit extract might reduce the efficacy of erlotinib.
In vitro research suggests that bilberry fruit extract and its constituents, delphinidin and delphinidin-3-O-glucoside, inhibit the activity of erlotinib. This interaction has not been reported in humans.

Likelihood Possible Evidence D
Bilberry full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Grape Seed Xtra 50 mg, from the product label.

Sundown Naturals

See all Sundown Naturals products
Web Address
www.sundownnaturals.com
Pharmacist Counseling Corner

Grape Seed Xtra 50 mg by Sundown Naturals: Common Questions

Does Grape Seed Xtra 50 mg by Sundown Naturals interact with any medications?
Yes. Based on its ingredients, Grape Seed Xtra 50 mg has a known interaction with 1,558 medications, including 13 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Grape Seed Xtra 50 mg contains 5 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Does green tea in this product really reduce how well my statin or blood pressure pill works?
Yes—the research shows green tea extract can significantly lower blood levels of atorvastatin (Lipitor) by about 24%, and nadolol by about 85%. If you take either of these, this product isn't safe to add without checking first with your doctor or pharmacist, because your medication might not work as intended.
What are the most common side effects I might feel?
Green tea can cause bloating, constipation, diarrhea, nausea, or indigestion, especially in larger amounts. Bilberry may cause dark stools, gas, or mild stomach discomfort. Selenium at normal doses is usually well tolerated, but excess can cause headache, rash, and hair loss.
Is this safe to take while pregnant or breastfeeding?
It depends on the ingredient. Green tea in moderate amounts is possibly safe in pregnancy, but high doses are not recommended. Bilberry fruit appears likely safe, but the supplement form lacks safety data. Citrus bioflavonoids and selenium lack enough information—talk with your doctor or pharmacist about whether it's right for you.
What is bilberry supposed to do, and does it actually work?
Bilberry is often promoted for night vision and cognitive decline, but the evidence doesn't support it—night vision benefit is rated possibly ineffective. Most other uses are rated as having insufficient evidence. Bilberry is generally safe as a food, though supplement safety is less well studied.
Why does this product have so many interactions with medications?
Green tea and selenium both affect how your liver and kidneys process many medications, and they can also interact with blood thinners and seizure drugs. Citrus bioflavonoids and bilberry work through similar pathways. Even a small dose of a multi-ingredient product can add up to real risks if you take prescription drugs.
Is selenium in this product safe?
Selenium at the recommended daily amount (no more than 400 mcg) is safe, but excess selenium can be toxic and cause hair loss, nail problems, fatigue, and in rare cases organ damage. This product does not state its selenium dose, so check the label and confirm it won't push you over the daily limit.

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

Not sure if Grape Seed Xtra 50 mg is safe with your meds?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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

Grape Seed Xtra 50 mg label
Go deeper

The Full Monographs Behind Grape Seed Xtra 50 mg’s Ingredients

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

Herb & supplement monograph

Green Tea

Interacts with 1,293 drugs

Green tea is a popular beverage rich in antioxidants called catechins, and drinking it in normal amounts is considered safe for most people. Concentrated green tea extracts are a different s...

Read the full Green Tea monograph → Herb & supplement monograph

Quercetin

Interacts with 1,169 drugs

Quercetin is a plant flavonoid with antioxidant and anti-inflammatory properties found in many common foods and sold as a supplement. While early research is interesting for allergies, blood...

Read the full Quercetin monograph → Herb & supplement monograph

Bilberry

Interacts with 275 drugs

Bilberry is a blueberry-like fruit rich in antioxidant plant compounds called anthocyanins, and it has a long history of traditional use for eye health, circulation, and mild diarrhea. While...

Read the full Bilberry monograph → Herb & supplement monograph

Selenium

Interacts with 321 drugs

Selenium is an essential trace mineral your body needs in small amounts for thyroid function, antioxidant defense, and immune health. Most people who eat a varied diet get enough, and supple...

Read the full Selenium monograph → Herb & supplement monograph

Grape

Interacts with 910 drugs

Grapes and grape products like grape seed extract contain antioxidant compounds such as resveratrol and proanthocyanidins that may support heart and blood vessel health. While the food is he...

Read the full Grape monograph →
Sources

Sources & How We Checked

Grape Seed Xtra 50 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 329 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.

Green Tea 219 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. Mitscher LA, Mitscher LA, Jung M, Shankel D, et al. Chemoprotection: a review of the potential therapeutic antioxidant properties of green tea (Camellia sinensis) and certain of its constituents. Med Res Rev 1997;17:327-65.
  8. Joeres R, Klinker H, Heusler H, et al. Influence of mexiletine on caffeine elimination. Pharmacol Ther 1987;33:163-9. PubMed
  9. 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.
  10. 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
  11. 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
  12. Booth SL, Madabushi HT, Davidson KW, et al. Tea and coffee brews are not dietary sources of vitamin K-1 (phylloquinone). J Am Diet Assoc 1995;95:82-3. PubMed
  13. Lou FQ, Zhang MF, Zhang XG, et al. A study on tea-pigment in prevention of atherosclerosis. Chin Med J (Engl) 1989;102:579-83.
  14. Graham HN. Green tea composition, consumption, and polyphenol chemistry. Prev Med 1992;21:334-50. PubMed
  15. 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
  16. 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.
  17. 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
  18. Eskenazi B. Caffeine—filtering the facts. N Engl J Med 1999;341:1688-9. PubMed
  19. 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
  20. 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
  21. 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
  22. FDA. Proposed rule: dietary supplements containing ephedrine alkaloids. Available at: www.verity.fda.gov (Accessed 25 January 2000).
  23. Weisburger JH. Tea and health: the underlying mechanisms. Proc Soc Exp Biol Med 1999;220:271-5. PubMed
  24. Taylor JR, Wilt VM. Probable antagonism of warfarin by green tea. Ann Pharmacother 1999;33:426-8. PubMed
  25. Briggs GB, Freeman RK, Yaffe SJ. Drugs in Pregnancy and Lactation. 5th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 1998.
  26. 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
  27. 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
  28. 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
  29. American Academy of Pediatrics. The transfer of drugs and other chemicals into human milk. Pediatrics 2001;108:776-89. PubMed
  30. Heck AM, DeWitt BA, Lukes AL. Potential interactions between alternative therapies and warfarin. Am J Health Syst Pharm 2000;57:1221-7. DOI
  31. Sinclair CJ, Geiger JD. Caffeine use in sports. A pharmacological review. J Sports Med Phys Fitness 2000;40:71-9.
  32. 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
  33. Ali M, Afzal M. A potent inhibitor of thrombin stimulated platelet thromboxane formation from unprocessed tea. Prostaglandins Leukot Med 1987;27:9-13. PubMed
  34. 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
  35. 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
  36. Pisters KM, Newman RA, Coldman B, et al. Phase I trial of oral green tea extract in adult patients with solid tumors. J Clin Oncol 2001;19:1830-8. PubMed
  37. 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
  38. 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
  39. 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
  40. 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
  41. McGowan JD, Altman RE, Kanto WP Jr. Neonatal withdrawal symptoms after chronic maternal ingestion of caffeine. South Med J 1988;81:1092-4.. PubMed
  42. Nehlig A, Debry G. Consequences on the newborn of chronic maternal consumption of coffee during gestation and lactation: a review. J Am Coll Nutr 1994;13:6-21.. PubMed
  43. Massey LK. Is caffeine a risk factor for bone loss in the elderly? Am J Clin Nutr 2001;74:569-70. PubMed
  44. Kockler DR, McCarthy MW, Lawson CL. Seizure activity and unresponsiveness after hydroxycut ingestion. Pharmacotherapy 2001;21:647-51.. PubMed
  45. 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
  46. Ahn WS, Yoo J, Huh SW, et al. Protective effects of green tea extracts (polyphenon E and EGCG) on human cervical lesions. Eur J Cancer Prev 2003;12:383-90. PubMed
  47. Infante S, Baeza ML, Calvo M, et al. Anaphylaxis due to caffeine. Allergy 2003;58:681-2. PubMed
  48. Massey LK, Whiting SJ. Caffeine, urinary calcium, calcium metabolism and bone. J Nutr 1993;123:1611-4. PubMed
  49. Shirai T, Hayakawa H, Akiyama J, et al. Food allergy to green tea. J Allergy Clin Immunol 2003;112:805-6. PubMed
  50. Jatoi A, Ellison N, Burch PA, et al. A phase II trial of green tea in the treatment of patients with androgen independent metastatic prostate carcinoma. Cancer 2003;97:1442-6.. PubMed
  51. Nawrot P, Jordan S, Eastwood J, et al. Effects of caffeine on human health. Food Addit Contam 2003;20:1-30. PubMed
  52. 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
  53. Brown NJ, Ryder D, Branch RA. A pharmacodynamic interaction between caffeine and phenylpropanolamine. Clin Pharmacol Ther 1991;50:363-71. PubMed
  54. 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
  55. 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
  56. Carrillo JA, Benitez J. Clinically significant pharmacokinetic interactions between dietary caffeine and medications. Clin Pharmacokinet 2000;39:127-53. PubMed
  57. Underwood DA. Which medications should be held before a pharmacologic or exercise stress test? Cleve Clin J Med 2002;69:449-50. PubMed
  58. 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
  59. 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.
  60. 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
  61. Dews PB, O'Brien CP, Bergman J. Caffeine: behavioral effects of withdrawal and related issues. Food Chem Toxicol 2002;40:1257-61. PubMed
  62. 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
  63. Yang YC, Lu FH, Wu JS, et al. The protective effect of habitual tea consumption on hypertension. Arch Intern Med 2004 26;164:1534-40. PubMed
  64. Son DJ, Cho MR, Jin YR, et al. Antiplatelet effect of green tea catechins: a possible mechanism through arachidonic acid pathway. Prostaglandins Leukot Essent Fatty Acids 2004;71:25-31. PubMed
  65. 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
  66. Winkelmayer WC, Stampfer MJ, Willett WC, Curhan GC. Habitual caffeine intake and the risk of hypertension in women. JAMA 2005;294:2330-5. PubMed
  67. 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
  68. Forrest WH Jr, Bellville JW, Brown BW Jr. The interaction of caffeine with pentobarbital as a nighttime hypnotic. Anesthesiology 1972;36:37-41. PubMed
  69. Lake CR, Rosenberg DB, Gallant S, et al. Phenylpropanolamine increases plasma caffeine levels. Clin Pharmacol Ther 1990;47:675-85. PubMed
  70. Bonkovsky HL. Hepatotoxicity associated with supplements containing Chinese green tea (Camellia sinensis). Ann Intern Med 2006;144:68-71.
  71. Gloro R, Hourmand-Ollivier I, Mosquet B, et al. Fulminant hepatitis during self-medication with hydroalcoholic extract of green tea. Eur J Gastroenterol Hepatol 2005;17:1135-7. PubMed
  72. Donovan JL, Chavin KD, Devane CL, et al. Green tea (Camellia sinensis) extract does not alter cytochrome P450 3A4 or 2D6 activity in healthy volunteers. Drug Metab Dispos 2004;32:906-8. PubMed
  73. Chu KO, Wang CC, Chu CY, et al. Pharmacokinetic studies of green tea catechins in maternal plasma and fetuses in rats. J Pharm Sci 2006;95:1372-81. PubMed
  74. Isbrucker RA, Edwards JA, Wolz E, et al. Safety studies on epigallocatechin gallate (EGCG) preparations. Part 3: teratogenicity and reproductive toxicity studies in rats. Food Chem Toxicol 2006;44:651-61. PubMed
  75. Navarro-Peran E, Cabezas-Herrera J, Garcia-Canovas F, et al. The antifolate activity of tea catechins. Cancer Res 2005;65:2059-64. PubMed
  76. Jimenez-Saenz M, Martinez-Sanchez, MDC. Acute hepatitis associated with the use of green tea infusions. J Hepatol 2006;44:616-9. PubMed
  77. Bradley Pharmaceuticals. Veregen Prescribing Information. October 2006.
  78. Correa A, Stolley A, Liu Y. Prenatal tea consumption and risks of anencephaly and spina bifida. Ann Epidemiol 2000;10:476-7. PubMed
  79. 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
  80. Savitz DA, Chan RL, Herring AH, et al. Caffeine and miscarriage risk. Epidemiology 2008;19:55-62. PubMed
  81. Golden ED, Lam PY, Kardosh A, et al. Green tea polyphenols block the anticancer effects of bortezomib and other boronic acid-based proteasome inhibitors. Blood 2009;113:5927-37. PubMed
  82. Misaka S, Yatabe J, Muller F, et al. Green Tea Ingestion Greatly Reduces Plasma Concentrations of Nadolol in Healthy Subjects. Clin Pharmacol Ther 2014. [Epub ahead of print]. PubMed
  83. Roth M, Timmermann BN, Hagenbuch B. Interactions of green tea catechins with organic anion-transporting polypeptides. Drug Metab Dispos 2011;39:920-6. PubMed
  84. Kato Y, Miyazaki T, Kano T, et al. Involvement of influx and efflux transport systems in gastrointestinal absorption of celiprolol. J Pharm Sci 2009;98:2529-39. PubMed
  85. Chan, H. T., So, L. T., Li, S. W., Siu, C. W., Lau, C. P., and Tse, H. F. Effect of herbal consumption on time in therapeutic range of warfarin therapy in patients with atrial fibrillation. J.Cardiovasc.Pharmacol. 2011;58(1):87-90. PubMed
  86. Nishikawa, M., Ariyoshi, N., Kotani, A., Ishii, I., Nakamura, H., Nakasa, H., Ida, M., Nakamura, H., Kimura, N., Kimura, M., Hasegawa, A., Kusu, F., Ohmori, S., Nakazawa, K., and Kitada, M. Effects of continuous ingestion of green tea or grape seed extrac
  87. 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.
  88. 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
  89. 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
  90. 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
  91. 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
  92. 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
  93. 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.
  94. 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
  95. 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
  96. 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.
  97. 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
  98. 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.
  99. 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
  100. 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
  101. 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.
  102. 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
  103. Wang, X. and Yeung, J. H. Effects of the aqueous extract from Salvia miltiorrhiza Bunge on caffeine pharmacokinetics and liver microsomal CYP1A2 activity in humans and rats. J Pharm Pharmacol 2010;62(8):1077-1083.
  104. Kot M, Daniel WA. Caffeine as a marker substrate for testing cytochrome P450 activity in human and rat. Pharmacol Rep 2008;60:789-97.
  105. Kjaerstad MB, Nielsen F, Nohr-Jensen L, et al. Systemic uptake of miconazole during vaginal suppository use and effect on CYP1A2 and CYP3A4 associated enzyme activities in women. Eur J Clin Pharmacol 2010;66:1189-97. PubMed
  106. Goh BC, Reddy NJ, Dandamudi UB, et al. An evaluation of the drug interaction potential of pazopanib, an oral vascular endothelial growth factor receptor tyrosine kinase inhibitor, using a modified Cooperstown 5+1 cocktail in patients with advanced solid t
  107. Chen Y, Kang Z, Yan J, et al. Liu wei di huang wan, a well-known traditional Chinese medicine induces CYP1A2 while suppressing CYP2A6 and N-acetyltransferase 2 acivities in man. J Ethnopharmacol 2010;132:213-8.
  108. Suzuki S, Murayama Y, Sugiyama E, et al. Estimating pediatric doses of drugs metabolized by cytochrome P450 (CYP) isozymes, based on physiological liver development and serum protein levels. Yakugaku Zasshi 2010;130:613-20. PubMed
  109. Chien CF, Wu YT, Lee WC, et al. Herb-drug interaction of Andrographis paniculata extract and andrographolide on the pharmacokinetics of theophylline in rats. Chem Biol Interact 2010;184:458-65. PubMed
  110. Mills BM, Zaya MJ, Walters RR, et al. Current cytochrome P450 phenotyping methods applied to metabolic drug -drug interaction prediction in dogs. Drug Metab Dispos 2010;38:396-404. PubMed
  111. Turpault S, Brian W, Van Horn R, et al. Pharmacokinetic assessment of a five-probe cocktail for CYPs 1A2, 2C9, 2C19, 2D6, and 3A. Br J Clin Pharmacol 2009;68:928-35. PubMed
  112. Filimonova AA, Ziganshina LE, Ziganshin AU, Chichirov AA. On the possibility of patient phenotyping on the basis of cytochrome p-450 1A2 isoenzyme activity using caffeine as the test substrate. Eksp Klin Farmakol 2009;72:61-5.
  113. Jenkins J, Williams D, Deng Y, et al. Eltrombopag, an oral thrombopoietin receptor agonist, has no impact on the pharmacokinetic profile of probe drugs for cytochrome P450 isoenzymes CYP3A4, CYP1A2, CYP2C9 and CYP2C19 in healthy men: a cocktail analysis.
  114. Chow, H. H., Cai, Y., Hakim, I. A., Crowell, J. A., Shahi, F., Brooks, C. A., Dorr, R. T., Hara, Y., and Alberts, D. S. Pharmacokinetics and safety of green tea polyphenols after multiple-dose administration of epigallocatechin gallate and polyphenon E i
  115. Gross, G., Meyer, K. G., Pres, H., Thielert, C., Tawfik, H., and Mescheder, A. A randomized, double-blind, four-arm parallel-group, placebo-controlled Phase II/III study to investigate the clinical efficacy of two galenic formulations of Polyphenon E in
  116. Stockfleth, E., Beti, H., Orasan, R., Grigorian, F., Mescheder, A., Tawfik, H., and Thielert, C. Topical Polyphenon E in the treatment of external genital and perianal warts: a randomized controlled trial. Br.J Dermatol. 2008;158(6):1329-1338.
  117. 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
  118. 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
  119. 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
  120. 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
  121. 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
  122. 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
  123. 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
  124. 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
  125. 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
  126. 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
  127. 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
  128. 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
  129. Clausen, T. Hormonal and pharmacological modification of plasma potassium homeostasis. Fundam.Clin Pharmacol 2010;24(5):595-605. PubMed
  130. Gronroos, N. N. and Alonso, A. Diet and risk of atrial fibrillation - epidemiologic and clinical evidence -. Circ.J 2010;74(10):2029-2038. PubMed
  131. Perera, V., Gross, A. S., and McLachlan, A. J. Caffeine and paraxanthine HPLC assay for CYP1A2 phenotype assessment using saliva and plasma. Biomed.Chromatogr. 2010;24(10):1136-1144. PubMed
  132. 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
  133. Izzo, A. A. and Ernst, E. Interactions between herbal medicines and prescribed drugs: an updated systematic review. Drugs 2009;69(13):1777-1798. PubMed
  134. Laurie, S. A., Miller, V. A., Grant, S. C., Kris, M. G., and Ng, K. K. Phase I study of green tea extract in patients with advanced lung cancer. Cancer Chemother.Pharmacol. 2005;55(1):33-38. PubMed
  135. Chiu, A. E., Chan, J. L., Kern, D. G., Kohler, S., Rehmus, W. E., and Kimball, A. B. Double-blinded, placebo-controlled trial of green tea extracts in the clinical and histologic appearance of photoaging skin. Dermatol Surg. 2005;31(7 Pt 2):855-860. PubMed
  136. Javaid, A. and Bonkovsky, H. L. Hepatotoxicity due to extracts of Chinese green tea (Camellia sinensis): a growing concern. J Hepatol 2006;45(2):334-335. PubMed
  137. Martinez-Sierra, C., Rendon, Unceta P., and Martin, Herrera L. [Acute hepatitis after green tea ingestion]. Med Clin (Barc.) 6-17-2006;127(3):119.
  138. Molinari, M., Watt, K. D., Kruszyna, T., Nelson, R., Walsh, M., Huang, W. Y., Nashan, B., and Peltekian, K. Acute liver failure induced by green tea extracts: case report and review of the literature. Liver Transpl. 2006;12(12):1892-1895. PubMed
  139. Chow, H. H., Hakim, I. A., Vining, D. R., Crowell, J. A., Cordova, C. A., Chew, W. M., Xu, M. J., Hsu, C. H., Ranger-Moore, J., and Alberts, D. S. Effects of repeated green tea catechin administration on human cytochrome P450 activity. Cancer Epidemiol.B PubMed
  140. Federico, A., Tiso, A., and Loguercio, C. A case of hepatotoxicity caused by green tea. Free Radic.Biol Med 8-1-2007;43(3):474. PubMed
  141. Sarma, D. N., Barrett, M. L., Chavez, M. L., Gardiner, P., Ko, R., Mahady, G. B., Marles, R. J., Pellicore, L. S., Giancaspro, G. I., and Low, Dog T. Safety of green tea extracts : a systematic review by the US Pharmacopeia. Drug Saf 2008;31(6):469-484. PubMed
  142. Engdal, S. and Nilsen, O. G. In vitro inhibition of CYP3A4 by herbal remedies frequently used by cancer patients. Phytother.Res. 2009;23(7):906-912.
  143. Bergman, J. and Schjott, J. Hepatitis caused by Lotus-f3? Basic Clin Pharmacol.Toxicol. 2009;104(5):414-416. PubMed
  144. Kalus, U., Kiesewetter, H., and Radtke, H. Effect of CYSTUS052 and green tea on subjective symptoms in patients with infection of the upper respiratory tract. Phytother.Res. 2010;24(1):96-100.
  145. Tatti, S., Stockfleth, E., Beutner, K. R., Tawfik, H., Elsasser, U., Weyrauch, P., and Mescheder, A. Polyphenon E: a new treatment for external anogenital warts. Br.J Dermatol. 2010;162(1):176-184.
  146. Tsao, A. S., Liu, D., Martin, J., Tang, X. M., Lee, J. J., El-Naggar, A. K., Wistuba, I., Culotta, K. S., Mao, L., Gillenwater, A., Sagesaka, Y. M., Hong, W. K., and Papadimitrakopoulou, V. Phase II randomized, placebo-controlled trial of green tea extra
  147. Liatsos, G. D., Moulakakis, A., Ketikoglou, I., and Klonari, S. Possible green tea-induced thrombotic thrombocytopenic purpura. Am.J Health Syst.Pharm. 4-1-2010;67(7):531-534. PubMed
  148. Josic, J., Olsson, A. T., Wickeberg, J., Lindstedt, S., and Hlebowicz, J. Does green tea affect postprandial glucose, insulin and satiety in healthy subjects: a randomized controlled trial. Nutr.J. 2010;9:63. PubMed
  149. Miller, R. J., Jackson, K. G., Dadd, T., Mayes, A. E., Brown, A. L., and Minihane, A. M. The impact of the catechol-O-methyltransferase genotype on the acute responsiveness of vascular reactivity to a green tea extract. Br.J.Nutr. 2011;105(8):1138-1144.
  150. Rohde, J., Jacobsen, C., and Kromann-Andersen, H. [Toxic hepatitis triggered by green tea]. Ugeskr.Laeger 1-17-2011;173(3):205-206.
  151. Tzellos, T. G., Sardeli, C., Lallas, A., Papazisis, G., Chourdakis, M., and Kouvelas, D. Efficacy, safety and tolerability of green tea catechins in the treatment of external anogenital warts: a systematic review and meta-analysis. J.Eur.Acad.Dermatol.Ve PubMed
  152. Otera, H., Tada, K., Sakurai, T., Hashimoto, K., and Ikeda, A. Hypersensitivity pneumonitis associated with inhalation of catechin-rich green tea extracts. Respiration 2011;82(4):388-392. PubMed
  153. Yellapu, R. K., Mittal, V., Grewal, P., Fiel, M., and Schiano, T. Acute liver failure caused by 'fat burners' and dietary supplements: a case report and literature review. Can.J.Gastroenterol. 2011;25(3):157-160. PubMed
  154. Karth, A., Holoshitz, N., Kavinsky, C. J., Trohman, R., and McBride, B. F. A case report of atrial fibrillation potentially induced by hydroxycut: a multicomponent dietary weight loss supplement devoid of sympathomimetic amines. J.Pharm.Pract. 2010;23(3) PubMed
  155. Hsu, C. H., Liao, Y. L., Lin, S. C., Tsai, T. H., Huang, C. J., and Chou, P. Does supplementation with green tea extract improve insulin resistance in obese type 2 diabetics? A randomized, double-blind, and placebo-controlled clinical trial. Altern.Med.R
  156. Zheng XX, Xu YL, Li SH, et al. Green tea intake lowers fasting serum total and LDL cholesterol in adults: a meta-analysis of 14 randomized controlled trials. Am.J.Clin.Nutr. 2011;94:601-610. PubMed
  157. Miller, R. J., Jackson, K. G., Dadd, T., Mayes, A. E., Brown, A. L., Lovegrove, J. A., and Minihane, A. M. The impact of the catechol-O-methyltransferase genotype on vascular function and blood pressure after acute green tea ingestion. Mol.Nutr.Food Res.
  158. Bogdanski, P., Suliburska, J., Szulinska, M., Stepien, M., Pupek-Musialik, D., and Jablecka, A. Green tea extract reduces blood pressure, inflammatory biomarkers, and oxidative stress and improves parameters associated with insulin resistance in obese, h
  159. Jurgens, T. M., Whelan, A. M., Killian, L., Doucette, S., Kirk, S., and Foy, E. Green tea for weight loss and weight maintenance in overweight or obese adults. Cochrane.Database.Syst.Rev. 2012;12:CD008650. PubMed
  160. Sakamoto, O., Saita, N., Yamasaki, H., Tamanoi, M., and Ando, M. Pulmonary granulomatosis caused by aspirated green tea. Chest 1994;106(1):308-309. PubMed
  161. Jiménez-Encarnación E, Ríos G, Muñoz-Mirabal A, Vilá LM. Euforia-induced acute hepatitis in a patient with scleroderma. BMJ Case Rep 2012;2012. PubMed
  162. Choi JS, Burm JP. Effects of oral epigallocatechin gallate on the pharmacokinetics of nicardipine in rats. Arch Pharm Res. 2009 Dec;32(12):1721-5. PubMed
  163. Chung JH, Choi DH, Choi JS. Effects of oral epigallocatechin gallate on the oral pharmacokinetics of verapamil in rats. Biopharm Drug Dispos. 2009 Mar;30(2):90-3. PubMed
  164. Crew KD, Brown P, Greenlee H, Bevers TB, Arun B, Hudis C, McArthur HL, Chang J, Rimawi M, Vornik L, Cornelison TL, Wang A, Hibshoosh H, Ahmed A, Terry MB, Santella RM, Lippman SM, Hershman DL. Phase IB randomized, double-blinded, placebo-controlled, dose
  165. Dryden GW, Lam A, Beatty K, Qazzaz HH, McClain CJ. A pilot study to evaluate the safety and efficacy of an oral dose of (-)-epigallocatechin-3-gallate-rich polyphenon E in patients with mild to moderate ulcerative colitis. Inflamm Bowel Dis. 2013 Aug;19(9 PubMed
  166. Gallo E, Maggini V, Berardi M, Pugi A, Notaro R, Talini G, Vannozzi G, Bagnoli S, Forte P, Mugelli A, Annese V, Firenzuoli F, Vannacci A. Is green tea a potential trigger for autoimmune hepatitis? Phytomedicine. 2013 Oct 15;20(13):1186-9. PubMed
  167. Liu K, Zhou R, Wang B, Chen K, Shi LY, Zhu JD, Mi MT. Effect of green tea on glucose control and insulin sensitivity: a meta-analysis of 17 randomized controlled trials. Am J Clin Nutr. 2013 Aug;98(2):340-8. PubMed
  168. Onakpoya I, Spencer E, Heneghan C, Thompson M. The effect of green tea on blood pressure and lipid profile: a systematic review and meta-analysis of randomized clinical trials. Nutr Metab Cardiovasc Dis. 2014 Aug;24:823-36. PubMed
  169. Patel SS, Beer S, Kearney DL, Phillips G, Carter BA. Green tea extract: a potential cause of acute liver failure. World J Gastroenterol. 2013 Aug 21;19(31):5174-7. PubMed
  170. Pillukat MH, Bester C, Hensel A, Lechtenberg M, Petereit F, Beckebaum S, Müller KM, Schmidt HH. Concentrated green tea extract induces severe acute hepatitis in a 63-year-old woman--a case report with pharmaceutical analysis. J Ethnopharmacol. 2014 Aug 8; PubMed
  171. Schönthal AH. Adverse effects of concentrated green tea extracts. Mol Nutr Food Res. 2011 Jun;55(6):874-85. PubMed
  172. Shiraishi M, Haruna M, Matsuzaki M, Ota E, Murayama R, Murashima S. Association between the serum folate levels and tea consumption during pregnancy. Biosci Trends. 2010 Oct;4(5):225-30.
  173. Jang EH, Choi JY, Park CS, Lee SK, Kim CE, Park HJ, Kang JS, Lee JW, Kang JH. Effects of green tea extract administration on the pharmacokinetics of clozapine in rats. J Pharm Pharmacol. 2005 Mar;57(3):311-6. PubMed
  174. Trudel D, Labbé DP, Araya-Farias M, Doyen A, Bazinet L, Duchesne T, Plante M, Grégoire J, Renaud MC, Bachvarov D, Têtu B, Bairati I. A two-stage, single-arm, phase II study of EGCG-enriched green tea drink as a maintenance therapy in women with advanced s
  175. Zheng XX, Xu YL, Li SH, Hui R, Wu YJ, Huang XH. Effects of green tea catechins with or without caffeine on glycemic control in adults: a meta-analysis of randomized controlled trials. Am J Clin Nutr. 2013 Apr;97(4):750-62. PubMed
  176. 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
  177. 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
  178. 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
  179. 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
  180. Health Canada. Health Product Info Watch. October 2016; 5-6. Available at: http://www.hc-sc.gc.ca/dhp-mps/medeff/bulletin/hpiw-ivps_2016-10-eng.php#a15.
  181. Green Tea Extract-Containing Natural Health Products - Rare Risk of Serious Liver Injury. Recalls & alerts. November 15, 2017. http://healthycanadians.gc.ca/recall-alert-rappel-avis/hc-sc/2017/65100a-eng.php. Accessed November 10, 2017.
  182. Mazzanti G, Di Sotto A, Vitalone A. Hepatotoxicity of green tea: an update. Arch Toxicol. 2015;89(8):1175-91. PubMed
  183. Isomura T, Suzuki S, Origasa H, et al. Liver-related safety assessment of green tea extracts in humans: a systematic review of randomized controlled trials. Eur J Clin Nutr. 2016;70(11):1221-1229. PubMed
  184. Drug Record: Green Tea (Camellia Sinesis). LiverTox: National Institutes of Health, U.S. Department of Health & Human Services, March 2014. https://livertox.nlm.nih.gov//GreenTea.htm. Accessed November 20, 2017.
  185. Yates AA, Erdman JW Jr, Shao A, Dolan LC, Griffiths JC. Bioactive nutrients - Time for tolerable upper intake levels to address safety. Regul Toxicol Pharmacol. 2017;84:94-101. PubMed
  186. Younes M, Aggett P, Aguilar F, et al. EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS). Scientific opinion on the safety of green tea catechins. EFSA Journal 2018;16(4):5239. PubMed
  187. 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
  188. Dostal AM, Samavat H, Bedell S, et al. The safety of green tea extract supplementation in postmenopausal women at risk for breast cancer: results of the Minnesota Green Tea Trial. Food Chem Toxicol. 2015 Sep;83:26-35. PubMed
  189. Shamekhi Z, Amani R, Habibagahi Z, Namjoyan F, Ghadiri A, Saki Malehi A. A Randomized, Double-blind, Placebo-controlled Clinical Trial Examining the Effects of Green Tea Extract on Systemic Lupus Erythematosus Disease Activity and Quality of Life. Phytoth PubMed
  190. 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
  191. Voskoboinik A, Kalman JM, Kistler PM. Caffeine and arrhythmias: time to grind the data. JACC: Clin Electrophysiol. 2018;4(4):425-32. PubMed
  192. Chong SJ, Howard KA, Knox C. Hypokalaemia and drinking green tea: a literature review and report of 2 cases. BMJ Case Rep. 2016;2016. pii: bcr2016214425. PubMed
  193. Qiao J, Gu C, Shang W, et al. Effect of green tea on pharmacokinetics of 5-fluorouracil in rats and pharmacodynamics in human cell lines in vitro. Food Chem Toxicol. 2011;49(6):1410-5. PubMed
  194. Abe O, Ono T, Sato H, et al. Role of (-)-epigallocatechin gallate in the pharmacokinetic interaction between nadolol and green tea in healthy volunteers. Eur J Clin Pharmacol 2018;74(6):775-83. doi: 10.1007/s00228-018-2436-2. PubMed
  195. 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
  196. Nutescu EA, Shapiro NL, Ibrahim S, et al. Warfarin and its interactions with foods, herbs and other dietary supplements. Expert Opin Drug Saf. 2006;5(3):433-51. PubMed
  197. Abdelkawy KS, Abdelaziz RM, Abdelmageed AM, Donia AM, El-Khodary NM. Effects of green tea extract on atorvastatin pharmacokinetics in healthy volunteers. Eur J Drug Metab Pharmacokinet. 2020;45(3):351-360. PubMed
  198. Filippini T, Malavolti M, Borrelli F, et al. Green tea (Camellia sinensis) for the prevention of cancer. Cochrane Database Syst Rev. 2020;3(3):CD005004. PubMed
  199. Huang S, Xu Q, Liu L, et al. Effect of green tea and (-)-epigallocatechin gallate on the pharmacokinetics of rosuvastatin. Curr Drug Metab. 2020. PubMed
  200. Mahmoodi M, Hosseini R, Kazemi A, Ofori-Asenso R, Mazidi M, Mazloomi SM. Effects of green tea or green tea catechin on liver enzymes in healthy individuals and people with nonalcoholic fatty liver disease: A systematic review and meta-analysis of randomiz
  201. Misaka S, Abe O, Ono T, et al. Effects of single green tea ingestion on pharmacokinetics of nadolol in healthy volunteers. Br J Clin Pharmacol. 2020. PubMed
  202. Oketch-Rabah HA, Roe AL, Rider CV, et al. United States Pharmacopeia (USP) comprehensive review of the hepatotoxicity of green tea extracts. Toxicol Rep. 2020;7:386-402. PubMed
  203. Kim TE, Ha N, Kim Y, et al. Effect of epigallocatechin-3-gallate, major ingredient of green tea, on the pharmacokinetics of rosuvastatin in healthy volunteers. Drug Des Devel Ther. 2017;11:1409-1416. PubMed
  204. Misaka S, Ono Y, Uchida A, et al. Impact of green tea catechin ingestion on the pharmacokinetics of lisinopril in healthy volunteers. Clin Transl Sci. 2020. PubMed
  205. Darweesh RS, El-Elimat T, Zayed A, et al. The effect of grape seed and green tea extracts on the pharmacokinetics of imatinib and its main metabolite, N-desmethyl imatinib, in rats. BMC Pharmacol Toxicol. 2020;21(1):77. PubMed
  206. Sonoda J, Ogata K, Yoshikawa N, Sato K, Ikeda R, Shimodozono Y. Impact of green tea intake on the pharmacokinetics of celiprolol in healthy subjects. Int J Clin Pharmacol Ther. 2020. PubMed
  207. Kim S, Park TH, Kim WI, Park S, Kim JH, Cho MK. The effects of green tea on acne vulgaris: A systematic review and meta-analysis of randomized clinical trials. Phytother Res. 2021;35(1):374-383. PubMed
  208. Percevault S, Charpiat B, Lebossé F, Mabrut JY, Vial T, Colom M. Green tea and hepatoxicity: Two case reports. Therapie 2021. PubMed
  209. Kajita N, Miyama S, Kinoshita K, Yoshida K, Narita M. Green tea-induced anaphylaxis: The first pediatric case report. Allergol Int 2021;70(4):507-508. PubMed
  210. 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
  211. 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
  212. 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
  213. 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
  214. Seufferlein T, Ettrich TJ, Menzler S, et al. Green tea extract to prevent colorectal adenomas, results of a randomized, placebo-controlled clinical trial. Am J Gastroenterol 2022;117(6):884-894. PubMed
  215. Teramoto M, Yamagishi K, Muraki I, Tamakoshi A, Iso H. Coffee and green tea consumption and cardiovascular disease mortality among people with and without hypertension. J Am Heart Assoc 2023;12(2):e026477. PubMed
  216. Veerman GDM, van der Werff SC, Koolen SLW, et al. The influence of green tea extract on nintedanib's bioavailability in patients with pulmonary fibrosis. Biomed Pharmacother 2022;151:113101. PubMed
  217. Misaka S, Ono Y, Taudte RV, et al. Exposure of fexofenadine, but not pseudoephedrine, is markedly decreased by green tea extract in healthy volunteers. Clin Pharmacol Ther 2022;112(3):627-634. PubMed
  218. Zhao H, Zhu W, Zhao X, et al. Efficacy of epigallocatechin-3-gallate in preventing dermatitis in patients with breast cancer receiving postoperative radiotherapy: A double-blind, placebo-controlled, phase 2 randomized clinical trial. JAMA Dermatol 2022;15 PubMed
  219. Pochet S, Lechon AS, Lescrainier C, et al. Herb-anticancer drug interactions in real life based on VigiBase, the WHO global database. Sci Rep 2022;12(1):14178. PubMed

See these in context on the Green Tea monograph →

Quercetin 26 references
  1. Shoskes DA, Zeitlin SI, Shahed A, Rajfer J. Quercetin in men with category III chronic prostatitis: A preliminary prospective, double-blind, placebo-controlled trial. Urol 1999;54:960-3. PubMed
  2. Starvic B. Quercetin in our diet: from potent mutagen to probable anticarcinogen. Clin Biochem 1994;27:245-8. PubMed
  3. Ferry DR, Smith A, Malkhandi J, et al. Phase I clinical trial of the flavonoid quercetin: Pharmacokinetics and evidence for in vivo tyrosine kinase inhibition. Clin Cancer Res 1996;2:659-67..
  4. Obach RS. Inhibition of human cytochrome P450 enzymes by constituents of St. John's wort, an herbal preparation used in the treatment of depression. J Pharmacol Exp Ther 2000;294:88-95. DOI
  5. Edwards RL, Lyon T, Litwin SE, et al. Quercetin reduces blood pressure in hypertensive subjects. J Nutr 2007;137:2405-11.
  6. Kim KA, Park PW, Kim HK, et al. Effect of quercetin on the pharmacokinetics of rosiglitazone, a CYP2C8 substrate, in healthy subjects. J Clin Pharmacol 2005;45:941-6. PubMed
  7. DiCenzo R, Frerichs V, Larppanichpoonphol P, et al. Effect of quercetin on the plasma and intracellular concentrations of saquinavir in healthy adults. Pharmacotherapy 2006;26:1255-61. PubMed
  8. Choi JS, Choi BC, Choi KE. Effect of quercetin on the pharmacokinetics of oral cyclosporine. Am J Health Syst Pharm 2004;61:2406-9. PubMed
  9. Choi JS, Jo BW, Kim YC. Enhanced paclitaxel bioavailability after oral administration of paclitaxel or prodrug to rats pretreated with quercetin. Eur J Pharm Biopharm 2004;57:313-8. PubMed
  10. Vaclavikova R, Horsky S, Simek P, Gut I. Paclitaxel metabolism in rat and human liver microsomes is inhibited by phenolic antioxidants. Naunyn Schmiedebergs Arch Pharmacol 2003;368:200-9. PubMed
  11. Di Bari L, Ripoli S, Pradhan S, Salvadori P. Interactions between quercetin and warfarin for albumin binding: A new eye on food/drug interference. Chirality 2010;22:593-6. PubMed
  12. Lamson, D. W. and Brignall, M. S. Antioxidants and cancer, part 3: quercetin. Altern.Med.Rev. 2000;5(3):196-208.
  13. Duan KM, Wang SY, Ouyang W, Mao YM, Yang LJ. Effect of quercetin on CYP3A activity in Chinese healthy participants. J Clin Pharmacol 2012;52(6):940-6. PubMed
  14. Wang SY, Duan KM, Li Y, et al. Effect of quercetin on P-glycoprotein transport ability in Chinese healthy subjects. Eur J Clin Nutr 2013;67(4):390-4. PubMed
  15. Nguyen MA, Staubach P, Wolffram S, Langguth P. Effect of single-dose and short-term administration of quercetin on the pharmacokinetics of talinolol in humans - Implications for the evaluation of transporter-mediated flavonoid-drug interactions. Eur J Pha PubMed
  16. Wu LX, Guo CX, Chen WQ, et al. Inhibition of the organic anion-transporting polypeptide 1B1 by quercetin: an in vitro and in vivo assessment. Br J Clin Pharmacol 2012;73(5):750-7.
  17. Ahrens MJ, Thompson DL. Effect of emulin on blood glucose in type 2 diabetics. J Med Food. 2013;16(3):211-5. PubMed
  18. Larson A, Witman MA, Guo Y, et al. Acute, quercetin-induced reductions in blood pressure in hypertensive individuals are not secondary to lower plasma angiotensin-converting enzyme activity or endothelin-1: nitric oxide. Nutr Res. 2012;32(8):557-64. PubMed
  19. Bedada SK, Neerati P. Evaluation of the effect of quercetin treatment on CYP2C9 enzyme activity of diclofenac in healthy human volunteers. Phytother Res. 2018 Feb;32(2):305-311. doi: 10.1002/ptr.5978. PubMed
  20. Zhao Q, Wei J, Zhang H. Effects of quercetin on the pharmacokinetics of losartan and its metabolite EXP3174 in rats. Xenobiotica 2019;49(5):563-8. PubMed
  21. Bhutani P, Rajanna PK, Paul AT. Impact of quercetin on pharmacokinetics of quetiapine: insights from in-vivo studies in wistar rats. Xenobiotica. 2020:1-7.
  22. Li C, Wang X, Bi Y, et al. Potent Inhibitors of Organic Anion Transporters 1 and 3 From Natural Compounds and Their Protective Effect on Aristolochic Acid Nephropathy. Toxicol Sci. 2020;175(2):279-291. PubMed
  23. Ni Y, Duan Z, Zhou D, et al. Identification of Structural Features for the Inhibition of OAT3-Mediated Uptake of Enalaprilat by Selected Drugs and Flavonoids. Front Pharmacol. 2020;11:802. PubMed
  24. Song YK, Yoon JH, Woo JK, et al. Quercetin is a flavonoid breast cancer resistance protein inhibitor with an impact on the oral pharmacokinetics of sulfasalazine in rats. Pharmaceutics 2020;12(5):397. PubMed
  25. Ahmad E, Jahangir M, Ismail MA, et al. Influence of quercetin pretreatment on pharmacokinetics of warfarin in rats. Curr Drug Saf 2022. PubMed
  26. Nambiar A, Kellogg D 3rd, Justice J, et al. Senolytics dasatinib and quercetin in idiopathic pulmonary fibrosis: results of a phase I, single-blind, single-center, randomized, placebo-controlled pilot trial on feasibility and tolerability. EBioMedicine 20 PubMed

See these in context on the Quercetin monograph →

Bilberry 14 references
  1. Cignarella A, Nastasi M, Cavalli E, Puglisi L. Novel lipid-lowering properties of Vaccinium myrtillus L. leaves, a traditional antidiabetic treatment, in several models of rat dyslipidaemia: a comparison with ciprofibrate. Thromb Res 1996;84:311-22. PubMed
  2. Morazzoni P, Magistretti MJ. Activity of Myrtocyan, an anthosyanoside complex from Vaccinium myrtillus (VMA), on platelet aggregation and adhesiveness. Fitoterapia 1990;61:13-21.
  3. Erlund, I., Koli, R., Alfthan, G., Marniemi, J., Puukka, P., Mustonen, P., Mattila, P., and Jula, A. Favorable effects of berry consumption on platelet function, blood pressure, and HDL cholesterol. Am J Clin Nutr 2008;87(2):323-331. PubMed
  4. Hawrelak, J. A. and Myers, S. P. Effects of two natural medicine formulations on irritable bowel syndrome symptoms: a pilot study. J Altern Complement Med 2010;16(10):1065-1071. PubMed
  5. Morazzoni P and Magistretti MJ. Effects of Vaccinium myrtillus anthocyanosides on prostacyclin-like activity in rat arterial issue. Fitoterapia 1986;57:11-14.
  6. Pulliero G, Montin S, Bettini V, and et al. Ex vivo study of the inhibitory effects of Vaccinium myrtillus anthocyanosides on human platelet aggregation. Fitoterapia 1989;60:69-75.
  7. Bottecchia D. Preliminary report on the inhibitory effect of vaccinium myrtillus anthocyanosides on platelet aggregation and clot retraction. Fitoterapia 1987;48:3-8.
  8. Fdez, M., Zaragoza, F., and Alvarez, P. In vitro platelet aggregation effects of anthocyanosides of vaccinium myrtilus L. Anales de la Real Academia de Farmacia 1983;49:79-90.
  9. Biedermann L, Mwinyi J, Scharl M, Frei P, Zeitz J, Kullak-Ublick GA, et al. Bilberry ingestion improves disease activity in mild to moderate ulcerative colitis-an open pilot study. 2013 May;7(4):271-9. PubMed
  10. Hoggard N, Cruickshank M, Moar KM, Bestwick C, Holst J, Russell W, et al. A single supplement of a standardized bilberry (Vaccinium myrtillus L.) extract (36% wet weight anthocyanins) modifies glycaemic response in individuals with type 2 diabetes control
  11. Aichinger G, Pahlke G, Nagel LJ, Berger W, Marko D. Bilberry extract, its major phenolic compounds, and soy isoflavone genistein antagonize the cytostatic drug erlotinib in human epithelial cells. Food Funct 2016;7(8):3628-36.
  12. Prokop J, Lněničková K, Cibicek N, et al. Effect of bilberry extract (Vaccinium myrtillus L.) on drug-metabolizing enzymes in rats. Food Chem Toxicol 2019;129:382-90. PubMed
  13. Chan SW, Chu TTW, Choi SW, Benzie IFF, Tomlinson B. Impact of short-term bilberry supplementation on glycemic control, cardiovascular disease risk factors, and antioxidant status in Chinese patients with type 2 diabetes. Phytother Res 2021. Online ahead o PubMed
  14. Bøhn SK, Myhrstad MCW, Thoresen M, et al. Bilberry/red grape juice decreases plasma biomarkers of inflammation and tissue damage in aged men with subjective memory impairment -a randomized clinical trial. BMC Nutr 2021;7(1):75. PubMed

See these in context on the Bilberry monograph →

Selenium 36 references
  1. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington, DC: National Academy Press, 2000. Available at: http://www.nap.edu/books/0309069351/html/.
  2. Brown BG, Zhao XQ, Chait A, et al. Simvastatin and niacin, antioxidant vitamins, or the combination for the prevention of coronary disease. N Engl J Med 2001;345:1583-93. DOI
  3. Trafikowska U, Zachara BA, Wiacek M, et al. Selenium supply and glutathione peroxidase activity in breastfed Polish infants. Acta Paediatr 1996;85:1143-5. PubMed
  4. Duffield-Lillico AJ, Slate EH, Reid ME, et al. Selenium supplementation and secondary prevention of nonmelanoma skin cancer in a randomized trial. J Natl Cancer Inst 2003;95:1477-81.. PubMed
  5. Cheung MC, Zhao XQ, Chait A, et al. Antioxidant supplements block the response of HDL to simvastatin-niacin therapy in patients with coronary artery disease and low HDL. Arterioscler Thromb Vasc Biol 2001;21:1320-6. PubMed
  6. Schiavon R, Freeman GE, Guidi GC, et al. Selenium enhances prostacyclin production by cultured endothelial cells: possible explanation for increased bleeding times in volunteers taking selenium as a dietary supplement. Thromb Res 1984;34:389-96. PubMed
  7. Davila JC, Edds GT, Osuna O, Simpson CF. Modification of the effects of aflatoxin B1 and warfarin in young pigs given selenium. Am J Vet Res 1983;44:1877-83. DOI
  8. Heese HD, Lawrence MA, Dempster WS, Pocock F. Reference concentrations of serum selenium and manganese in healthy nulliparas. S Afr Med J 1988;73:163-5.
  9. Lloyd B, Lloyd RS, Clayton BE. Effect of smoking, alcohol and other factors on the selenium status of a healthy population. J Epidemiol Commun Health 1983;37:213-7. PubMed
  10. Capel ID, Jenner M, Williams DC, et al. The effect of prolonged oral contraceptive steroid use on erythrocyte glutathione peroxidase activity. J Steroid Biochem 1981;14:729-32. PubMed
  11. Contempre B, Dumont JE, Ngo B, et al. Effect of selenium supplementation in hypothyroid subjects of an iodine and selenium deficient area: the possible danger of indiscriminate supplementation of iodine-deficient subjects with selenium. J Clin Endocrinol PubMed
  12. Hofbauer LC, Spitzweg C, Magerstadt RA, Heufelder AE. Selenium-induced thyroid dysfunction. Postgrad Med J 1997;73:103-4. PubMed
  13. Debski B, Milner JA. Dietary selenium supplementation prolongs pentobarbital induced hypnosis. J Nutr Biochem 2004;15:548-53. PubMed
  14. Ishikawa M, Sasaki M, Koiwai K, et al. Inhibition of hepatic mixed-function oxidase enzymes in mice by acute and chronic treatment with selenium. J Pharmacobiodyn 1992;15:377-85. PubMed
  15. Lippmann SM, Klein EA, Goodman PJ, et al. Effect of selenium and vitamin E on risk of prostate cancer and other cancers: the selenium and vitamin E cancer prevention trial (SELECT). JAMA 2009;301:39-51. DOI
  16. Reid SM, Middleton P, Cossich MC, Crowther CA. Interventions for clinical and subclinical hypothyroidism in pregnancy. Cochrane Database Syst Rev 2010;(7):CD007752. PubMed
  17. Vinceti, M., Wei, E. T., Malagoli, C., Bergomi, M., and Vivoli, G. Adverse health effects of selenium in humans. Rev.Environ.Health 2001;16(4):233-251. PubMed
  18. Abrams, C. K., Siram, S. M., Galsim, C., Johnson-Hamilton, H., Munford, F. L., and Mezghebe, H. Selenium deficiency in long-term total parenteral nutrition. Nutr Clin Pract 1992;7(4):175-178. PubMed
  19. Spiller, H. A. and Pfiefer, E. Two fatal cases of selenium toxicity. Forensic Sci Int 8-24-2007;171(1):67-72. PubMed
  20. Negro, R., Greco, G., Mangieri, T., Pezzarossa, A., Dazzi, D., and Hassan, H. The influence of selenium supplementation on postpartum thyroid status in pregnant women with thyroid peroxidase autoantibodies. J Clin Endocrinol.Metab 2007;92(4):1263-1268. PubMed
  21. Alexander, J. Selenium. Novartis.Found.Symp 2007;282:143-149.
  22. Salonen, J. T., Salonen, R., Seppanen, K., Rinta-Kiikka, S., Kuukka, M., Korpela, H., Alfthan, G., Kantola, M., and Schalch, W. Effects of antioxidant supplementation on platelet function: a randomized pair-matched, placebo-controlled, double-blind trial
  23. Kupka, R., Mugusi, F., Aboud, S., Msamanga, G. I., Finkelstein, J. L., Spiegelman, D., and Fawzi, W. W. Randomized, double-blind, placebo-controlled trial of selenium supplements among HIV-infected pregnant women in Tanzania: effects on maternal and chil
  24. Kamble, P., Mohsin, N., Jha, A., Date, A., Upadhaya, A., Mohammad, E., Khalil, M., Pakkyara, A., and Budruddin, M. Selenium intoxication with selenite broth resulting in acute renal failure and severe gastritis. Saudi.J Kidney Dis.Transpl. 2009;20(1):106
  25. Peretz, A., Neve, J., Desmedt, J., Duchateau, J., Dramaix, M., and Famaey, J. P. Lymphocyte response is enhanced by supplementation of elderly subjects with selenium-enriched yeast. Am.J Clin.Nutr. 1991;53(5):1323-1328. PubMed
  26. Kumpulainen, J., Salmenpera, L., Siimes, M. A., Koivistoinen, P., and Perheentupa, J. Selenium status of exclusively breast-fed infants as influenced by maternal organic or inorganic selenium supplementation. Am.J Clin.Nutr. 1985;42(5):829-835. PubMed
  27. Han, L. and Zhou, S. M. Selenium supplement in the prevention of pregnancy induced hypertension. Chin Med J (Engl) 1994;107(11):870-871.
  28. Kiremidjian-Schumacher, L., Roy, M., Wishe, H. I., Cohen, M. W., and Stotzky, G. Supplementation with selenium and human immune cell functions. II. Effect on cytotoxic lymphocytes and natural killer cells. Biol.Trace Elem.Res. 1994;41(1-2):115-127. PubMed
  29. Srivastava, A. K., Gupta, B. N., Bihari, V., and Gaur, J. S. Generalized hair loss and selenium exposure. Vet.Hum.Toxicol. 1995;37(5):468-469.
  30. Sudfeld CR, Aboud S, Kupka R, et al. Effect of selenium supplementation on HIV-1 RNA detection in breast milk of Tanzanian women. Nutrition 2014;30(9):1081-4. PubMed
  31. Rees K, Hartley L, Day C, et al. Selenium supplementation for the primary prevention of cardiovascular disease. Cochrane Database Syst Rev 2013;1:CD009671. PubMed
  32. Thompson PA, Ashbeck EL, Roe DJ, et al. Selenium Supplementation for Prevention of Colorectal Adenomas and Risk of Associated Type 2 Diabetes. J Natl Cancer Inst. 2016;108(12). PubMed
  33. Wichman J, Winther KH, Bonnema SJ, Hegedüs L. Selenium supplementation significantly reduces thyroid autoantibody levels in patients with chronic autoimmune thyroiditis: a systematic review and meta-analysis. Thyroid 2016;26(12):1681-92. PubMed
  34. Vinceti M, Filippini T, Rothman KJ. Selenium exposure and the risk of type 2 diabetes: a systematic review and meta-analysis. Eur J Epidemiol. 2018 Sep;33(9):789-810. Epub 2018 Jul 5. Review. PubMed
  35. Fallah S, Sani FV, Firoozrai M. Effect of contraceptive pill on the selenium and zinc status of healthy subjects. Contraception. 2009;80(1):40-3. PubMed
  36. Malpas CB, Vivash L, Genc S, et al. A Phase IIa Randomized Control Trial of VEL015 (Sodium Selenate) in Mild-Moderate Alzheimer's Disease. J Alzheimers Dis. 2016;54(1):223-232. PubMed

See these in context on the Selenium monograph →

Grape 34 references
  1. Kiesewetter H, Koscielny J, Kalus U, et al. Efficacy of orally administered extract of red vine leaf AS 195 (folia vitis viniferae) in chronic venous insufficiency (stages I-II). A randomized, double-blind, placebo-controlled trial. Arzneimittelforschung
  2. Xiao Dong S, Zhi Ping Z, Zhong Xiao W, et al. Possible enhancement of the first-pass metabolism of phenacetin by ingestion of grape juice in Chinese subjects. Br J Clin Pharmacol 1999;48:638-40. PubMed
  3. Vaswani SK, Hamilton RG, Carey RN, et al. Anaphylaxis recurrent urticaria and angioedema from grape hypersensitivity. J Allergy Clin Immunol 1998;101:S31.
  4. Chevallier A. The Encyclopedia of Medicinal Plants. London, UK: Dorling Kindersley, Ltd., 1996.
  5. Bernstein DI, Bernstein CK, Deng C, et al. Evaluation of the clinical efficacy and safety of grapeseed extract in the treatment of fall seasonal allergic rhinitis: a pilot study. Ann Allergy Asthma Immunol 2002;88:272-8.. PubMed
  6. Greenblatt DJ, von Moltke LL, Perloff ES, et al. Interaction of flurbiprofen with cranberry juice, grape juice, tea, and fluconazole: in vitro and clinical studies. Clin Pharmacol Ther 2006;79:125-33. PubMed
  7. Ward NC, Hodgson JM, Croft KD, et al. The combination of vitamin C and grape-seed polyphenols increases blood pressure: a randomized, double-blind, placebo-controlled trial. J Hypertens 2005;23:427-34.. PubMed
  8. Ray, S. D., Parikh, H., Hickey, E., Bagchi, M., and Bagchi, D. Differential effects of IH636 grape seed proanthocyanidin extract and a DNA repair modulator 4-aminobenzamide on liver microsomal cytochrome 4502E1-dependent aniline hydroxylation. Mol Cell B PubMed
  9. O'Byrne, D. J., Devaraj, S., Grundy, S. M., and Jialal, I. Comparison of the antioxidant effects of Concord grape juice flavonoids alpha-tocopherol on markers of oxidative stress in healthy adults. Am J Clin.Nutr. 2002;76(6):1367-1374.
  10. Schaefer, E., Peil, H., Ambrosetti, L., and Petrini, O. Oedema protective properties of the red vine leaf extract AS 195 (Folia vitis viniferae) in the treatment of chronic venous insufficiency. A 6-week observational clinical trial. Arzneimittelforschun PubMed
  11. Nishikawa, M., Ariyoshi, N., Kotani, A., Ishii, I., Nakamura, H., Nakasa, H., Ida, M., Nakamura, H., Kimura, N., Kimura, M., Hasegawa, A., Kusu, F., Ohmori, S., Nakazawa, K., and Kitada, M. Effects of continuous ingestion of green tea or grape seed extra
  12. de Lange, D. W., Scholman, W. L., Kraaijenhagen, R. J., Akkerman, J. W., and van de Wiel, A. Alcohol and polyphenolic grape extract inhibit platelet adhesion in flowing blood. Eur.J Clin.Invest 2004;34(12):818-824. PubMed
  13. Samet, J. M. and Coultas, D. B. Reduced forced vital capacity in California grape workers. What does it mean? Am Rev.Respir.Dis 1992;145(2 Pt 1):255-256. PubMed
  14. Gamsky, T. E., McCurdy, S. A., Samuels, S. J., and Schenker, M. B. Reduced FVC among California grape workers. Am Rev.Respir.Dis 1992;145(2 Pt 1):257-262. PubMed
  15. de Lange, D. W., Verhoef, S., Gorter, G., Kraaijenhagen, R. J., van de Wiel, A., and Akkerman, J. W. Polyphenolic grape extract inhibits platelet activation through PECAM-1: an explanation for the French paradox. Alcohol Clin.Exp.Res 2007;31(8):1308-1314 PubMed
  16. Etheridge, A. S., Black, S. R., Patel, P. R., So, J., and Mathews, J. M. An in vitro evaluation of cytochrome P450 inhibition and P-glycoprotein interaction with goldenseal, Ginkgo biloba, grape seed, milk thistle, and ginseng extracts and their constitu
  17. Krikorian, R., Nash, T. A., Shidler, M. D., Shukitt-Hale, B., and Joseph, J. A. Concord grape juice supplementation improves memory function in older adults with mild cognitive impairment. Br J Nutr. 2010;103(5):730-734. PubMed
  18. Ingersoll, G. L., Wasilewski, A., Haller, M., Pandya, K., Bennett, J., He, H., Hoffmire, C., and Berry, C. Effect of concord grape juice on chemotherapy-induced nausea and vomiting: results of a pilot study. Oncol.Nurs.Forum 2010;37(2):213-221. PubMed
  19. Oliveira-Freitas, V. L., Dalla, Costa T., Manfro, R. C., Cruz, L. B., and Schwartsmann, G. Influence of purple grape juice in cyclosporine bioavailability. J Ren Nutr. 2010;20(5):309-313. PubMed
  20. Hollis, J. H., Houchins, J. A., Blumberg, J. B., and Mattes, R. D. Effects of concord grape juice on appetite, diet, body weight, lipid profile, and antioxidant status of adults. J Am Coll.Nutr. 2009;28(5):574-582. PubMed
  21. Dohadwala, M. M., Hamburg, N. M., Holbrook, M., Kim, B. H., Duess, M. A., Levit, A., Titas, M., Chung, W. B., Vincent, F. B., Caiano, T. L., Frame, A. A., Keaney, J. F., Jr., and Vita, J. A. Effects of Concord grape juice on ambulatory blood pressure in
  22. Rabe, E., Stucker, M., Esperester, A., Schafer, E., and Ottillinger, B. Efficacy and tolerability of a red-vine-leaf extract in patients suffering from chronic venous insufficiency--results of a double-blind placebo-controlled study. Eur.J Vasc.Endovasc. PubMed
  23. Trotta, M., Cesaretti, M., Conzi, R., Derchi, L. E., and Borgonovo, G. Elderly male with mesogastric pain. Small bowel obstruction caused by an intact fresh grape. Ann.Emerg.Med 2011;58(4):e1-e2. PubMed
  24. McCurdy, S. A., Wiggins, P., Schenker, M. B., Munn, S., Shaieb, A. M., Weinbaum, Z., Goldsmith, D., McGillis, S. T., Berman, B., and Samuels, S. Assessing dermatitis in epidemiologic studies: occupational skin disease among California grape and tomato ha
  25. Winter, C. K. and Kurtz, P. H. Factors influencing grape worker susceptibility to skin rashes. Bull.Environ.Contam Toxicol. 1985;35(3):418-426. PubMed
  26. Yamasaki, R., Dekio, S., and Jidoi, J. Contact dermatitis from grape bud. Contact Dermatitis 1985;12(4):226-227. PubMed
  27. Cox, J. and Grigg, M. Small bowel obstruction by an intact grape. J Am Geriatr.Soc 1986;34(7):550. PubMed
  28. Faircloth, D. E. and Robison, W. J. Obstruction of the sigmoid colon by grape seeds. JAMA 11-27-1981;246(21):2430. PubMed
  29. Marguerie, C. and Drouet, M. [Occupational eosinophilic lung in a grape grower: role of sulfites]. Allerg.Immunol.(Paris) 1995;27(5):163-167.
  30. Brito, FF., Martinez, A., Palacios, R., Mur, P., Gomez, E., Galindo, P. A., Borja, J., and Martinez, J. Rhinoconjunctivitis and asthma caused by vine pollen: a case report. J Allergy Clin Immunol 1999;103(2 Pt 1):262-266. PubMed
  31. Ras RT, Zock PL, Zebregs YE, et al. Effect of polyphenol-rich grape seed extract on ambulatory blood pressure in subjects with pre- and stage I hypertension. Br J Nutr 2013;110(12):2234-41. PubMed
  32. Berry AC, Nakshabendi R, Abidali H, et al. Adverse effects of grape seed extract supplement: A clinical case and long-term follow-up. J Diet Suppl. 2016;13(2):232-5. PubMed
  33. Martínez-Maqueda D, Zapatera B, Gallego-Narbón A, Vaquero MP, Saura-Calixto F, Pérez-Jiménez J. A 6-week supplementation with grape pomace to subjects at cardiometabolic risk ameliorates insulin sensitivity, without affecting other metabolic syndrome mark
  34. Moon SW, Shin YU, Cho H, Bae SH, Kim HK; and for the Mogen Study Group. Effect of grape seed proanthocyanidin extract on hard exudates in patients with non-proliferative diabetic retinopathy. Medicine (Baltimore) 2019;98(21):e15515. PubMed

See these in context on the Grape monograph →

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

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

© 2021 Therapeutic Research Center, LLC

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