Major interaction on record — check this product against your medications before combining. Based on 3 of 4 ingredients. Check your meds →
Dietary supplement

Clear Thinking Ingredients & Drug Interactions

by Herb Stop

Clear Thinking label
See full label image
Capsule Category: Botanical
Most serious interaction: Major
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Clear Thinking 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

Clear Thinking is a dietary supplement by Herb Stop with 4 active ingredients. Its ingredients are commonly taken for memory and cognitive support, age-related mental decline, circulation problems.Based on those ingredients, 1,352 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Ginkgo biloba, American Ginseng. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Clear Thinking by Herb Stop

Ask about any prescription or over-the-counter medication and we check it for interactions with Clear Thinking by Herb Stop — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Clear Thinking by Herb Stop

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

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 12, 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 0 of its 4 active ingredients.
  • “Proprietary Blend” is a proprietary blend — the label gives one combined amount (346 mg) without saying how much of each component you get.

Clear Thinking has 4 ingredients total. The active ones are ginkgo biloba (a tree leaf extract), American ginseng (a root), and Icelandic moss (a lichen).

These are combined in a proprietary blend — meaning the label groups them together rather than listing each dose separately. The product also contains inactive ingredients: hydroxypropyl methylcellulose (a capsule binder) and purified water.

Does it work?

Moderate 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
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: Memory and cognitive support.
  • We looked for evidence on: Age-related cognitive decline, Cognitive function, Cognitive impairment, Dementia, Mental clarity, Brain fog — and 1 related terms.
  • The strongest evidence on file: Ginkgo is rated "Possibly Effective" for Dementia (Natural Medicines).
  • Also on file: Ginkgo is rated "Possibly Ineffective" for Age-related cognitive decline, Chemotherapy-related cognitive impairment.
  • Also on file: Ginkgo is rated "Insufficient Reliable Evidence To Rate" for Cognitive function, Cognitive impairment.

Ginkgo biloba is possibly effective for hearing loss, stroke recovery, schizophrenia, premenstrual syndrome, dementia, and anxiety, according to the evidence we hold. American ginseng is possibly effective for upper respiratory tract infections; the evidence on anemia and breast cancer is too limited to rate.

We have no effectiveness data on file for Icelandic moss.

The evidence, ingredient by ingredient Ginkgo American Ginseng Iceland Moss

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 3 of the 3 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 3 of 3.
  • General safety write-ups exist for 3 of 3.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Ginkgo biloba is generally well tolerated when taken orally for up to 6 years, but it carries a caution for bleeding risk — especially important if you're already on blood thinners. Dizziness and stomach upset are the most common side effects.

Rare but serious reports include heart rhythm problems (162 international cases, some fatal) and spontaneous bleeding, though in most bleeding cases other risk factors were present. The facts advise against ginkgo in pregnancy due to not enough safety data and possible bleeding risk; breastfeeding should be avoided.

American ginseng is generally well tolerated short-term and most commonly causes headache, but long-term safety isn't well studied. It's best avoided in pregnancy and breastfeeding.

Icelandic moss is generally well tolerated short-term but can irritate the stomach, and may contain lead if consumed as a primary food source for a long time; it should be avoided in pregnancy and breastfeeding.

Side effects, ingredient by ingredient Ginkgo American Ginseng Iceland Moss

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?
  • 2 of the 3 matched ingredients can interact with medications — Ginkgo, American Ginseng.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; seizure medications; immunosuppressants / transplant drugs; diabetes medications.
  • For scale: 1,353 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.

Double-check this product against blood thinners like warfarin, beta-blockers like talinolol, cholesterol drugs, anxiety medications, antidepressants, diabetes drugs, HIV medications, transplant rejection drugs, immunosuppressants, and MAOIs (older antidepressants). The most serious risks are with warfarin and talinolol.

Check your own medication Run your meds through the checker above

The bottom line

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

If you're taking any blood thinners, heart medications, diabetes drugs, or older antidepressants, talk to your pharmacist before starting this product — the interactions can be significant. This supplement is best avoided during pregnancy and breastfeeding.

Run your medications through the checker on this page to be sure.

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

Assessment coverage: 3 of 4 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Oct 24, 2023.

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 Clear Thinking, straight from the product label.

Brand Herb Stop
Net contents 300 Veggie Capsule(s)
Market status On market
Date entered into DSLD Oct 24, 2023
DSLD ID 297281
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, Adult (18 - 50 Years), Women (not pregnant or lactating), Dairy 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 Clear Thinking by Herb Stop, 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:
2 Capsule(s)
Servings per container
300
IngredientAmount% DV
Proprietary Blend346 mg--
Ginkgo biloba0 NP--
American Ginseng0 NP--
Icelandic Moss0 NP--
Poppy0 NP--

Other ingredients: Hydroxypropyl Methylcellulose, Water, Purified

Tap any ingredient to jump to its full detail below.

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

Suggested Use: Take 1 to 2 capsules 3 to 6 times per day with water, or as directed by your qualified healthcare professional.

Precautions

Avoid ingested red & orange food dye while using this product.

Safety Guideline: Contains poppy seeds.

Gingko may potentiate pharmaceutical MAO inhibitors. Not to be used during pregnancy or lactation. If you have a medical condition or take pharmaceutical drugs, please consult with your doctor before use.

Keep away from children.

Use only as directed on label.

Brand IP Statement(s)

Herb Stop Health In Your Own Hands

Formulation

Herbal Capsule

86% Organic content

Support for focus & concentration

Vegan & Cruelty-Free

Vegan & Cruelty-Free Made in the USA.

FDA Statement of Identity

Dietary Supplement

FDA Disclaimer Statement

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

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

See for yourself

Clear Thinking by Herb Stop label

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

Clear Thinking 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 Clear Thinking by Herb Stop

These are the 4 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Servings per container300 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.

Proprietary Blend

346 mg per serving

Other (inactive) ingredients: Hydroxypropyl Methylcellulose, Water, Purified. These complete the product’s ingredient list but are not active constituents.

Interaction report

Clear Thinking by Herb Stop Drug Interactions

Want to check YOUR meds against Clear Thinking?

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
1,352Drugs
3 Major 1,349 Moderate

Ingredients driving the most interactions

Ginkgo biloba 1,266
American Ginseng 217

Individual Drug Interactions

The ingredients in Clear Thinking interact with 1,352 drugs. Click any drug to see the details.

2 of the 4 ingredients in Clear Thinking interact with drugs. Each result below shows which ingredient is responsible. Ginkgo biloba American Ginseng

Each ingredient & the kinds of drugs it affects

For each ingredient in Clear Thinking 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.

Ginkgo biloba23 drug types · 1,266 drugs

Talinolol

Taking ginkgo with talinolol seems to increase blood levels of talinolol.
There is some evidence that using ginkgo leaf extract 120 mg orally three times daily for 14 days can increase levels of talinolol by 36% in healthy male individuals. However, single doses of ginkgo do not seem to affect talinolol pharmacokinetics.

Likelihood Probable Evidence B
Alprazolam (Xanax)

Theoretically, ginkgo might decrease the levels and clinical effects of alprazolam.
In clinical research, ginkgo extract (Ginkgold) 120 mg twice daily seems to decrease alprazolam levels by about 17%. However, ginkgo does not appear to decrease the elimination half-life of alprazolam. This suggests that ginkgo is more likely to decrease absorption of alprazolam rather than induce hepatic metabolism of alprazolam.

Likelihood Probable Evidence B
Anticoagulant/Antiplatelet Drugs

Ginkgo has been shown to increase the risk of bleeding in some people when taken with warfarin. Theoretically, ginkgo might increase the risk of bleeding if used with other anticoagulant or antiplatelet drugs.
Several pharmacodynamic studies suggest that ginkgo inhibits platelet aggregation. It is thought that the ginkgo constituent, ginkgolide B, displaces platelet-activating factor (PAF) from its binding sites, decreasing blood coagulation. Several case reports have documented serious bleeding events in patients taking ginkgo. However, population and clinical studies have produced mixed results. Some evidence shows that short-term use of ginkgo leaf does not significantly reduce platelet aggregation and blood clotting. A study in healthy males who took a specific ginkgo leaf extract (EGb 761) 160 mg twice daily for 7 days found no change in prothrombin time. An analysis of a large medical record database suggests that ginkgo increases the risk of a bleeding adverse event by 38% when taken concurrently with warfarin. It has been suggested that ginkgo has to be taken for at least 2-3 weeks to have a significant effect on platelet aggregation. However, a meta-analysis of 18 studies using standardized ginkgo extracts, 80-480 mg daily for up to 32 weeks, did not find a significant effect on platelet aggregation, fibrinogen concentration, or PT/aPTT. In addition, a single dose of ginkgo plus clopidogrel or ticlopidine does not seem to significantly increase bleeding time or platelet aggregation. Also, taking ginkgo leaf extract daily for 8 days in conjunction with rivaroxaban does not affect anti-factor Xa activity; however, this study did not evaluate bleeding time.

Likelihood Possible Evidence A
Anticonvulsants

Theoretically, ginkgo might reduce the effectiveness of anticonvulsants.
Ginkgo seeds contain ginkgotoxin. Large amounts of ginkgotoxin can cause neurotoxicity and seizure. Ginkgotoxin is present in much larger amounts in ginkgo seeds than leaves. Ginkgo leaf extract contains trace amounts of ginkgotoxin. The amount of ginkgotoxin in ginkgo leaf and leaf extract seems unlikely to cause toxicity. However, there are anecdotal reports of seizure occurring after use of ginkgo leaf both in patients without a history of seizure disorder and in those with previously well-controlled epilepsy.

Likelihood Possible Evidence D
Antidiabetes Drugs

Theoretically, taking ginkgo with antidiabetes drugs might alter the response to antidiabetes drugs.
Ginkgo leaf extract seems to alter insulin secretion and metabolism, and might affect blood glucose levels in people with type 2 diabetes. The effect of ginkgo seems to differ depending on the insulin and treatment status of the patient. In diet-controlled diabetes patients with hyperinsulinemia, taking ginkgo does not seem to significantly affect insulin or blood glucose levels. In patients with hyperinsulinemia who are treated with oral hypoglycemic agents, taking ginkgo seems to decrease insulin levels and increase blood glucose following an oral glucose tolerance test. Researchers speculate that this could be due to ginkgo-enhanced hepatic metabolism of insulin. In patients with pancreatic exhaustion, taking ginkgo seems to stimulate pancreatic beta-cells, resulting in increased insulin and C-peptide levels, but with no significant change in blood glucose levels in response to an oral glucose tolerance test.

Likelihood Possible Evidence B
Atorvastatin (Lipitor)

Theoretically, ginkgo might decrease the levels and clinical effects of atorvastatin.
In humans, intake of ginkgo extract appears to increase atorvastatin clearance, reducing the area under the curve of atorvastatin by 10% to 14% and the maximum concentration by 29%. However, this interaction does not appear to affect cholesterol synthesis and absorption. Further, a model in rats with hyperlipidemia suggests that administering ginkgo extract does not impact blood levels of atorvastatin and leads to lower total cholesterol, low-density lipoprotein cholesterol, and triglycerides when compared with rats given atorvastatin alone.

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

Theoretically, ginkgo might increase levels of drugs metabolized by CYP1A2.
Laboratory research suggests that ginkgo leaf extract can mildly inhibit CYP1A2 enzymes. However, clinical research suggests ginkgo might not affect CYP1A2. Until more is known, use ginkgo cautiously in patients taking drugs metabolized by these enzymes.

Likelihood Possible Evidence B
Cytochrome P450 2C19 (Cyp2C19) Substrates

Theoretically, ginkgo might decrease levels of drugs metabolized by CYP2C19.
Some clinical research shows that a specific ginkgo leaf extract (Remembrance, Herbs Product LTD) 140 mg twice daily can induce CYP2C19 enzymes and potentially decrease levels of drugs metabolized by these enzymes. However, other clinical research shows that taking ginkgo 120 mg twice daily for 12 days has no effect on levels of drugs metabolized by CYP2C19.

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

Theoretically, ginkgo might increase levels of drugs metabolized by CYP2C9.
In vitro, a specific standardized extract of ginkgo leaf (EGb 761) inhibits CYP2C9 activity . The terpenoid (ginkgolides) and flavonoid (quercetin, kaempferol, etc.) constituents seem to be responsible for this effect. Most ginkgo extracts contain some amount of these constituents. Therefore, other ginkgo leaf extracts might also inhibit the CYP2C9 enzyme. However, clinical research suggests that ginkgo might not have a significant effect on CYP2C9 in humans. Ginkgo does not seem to significantly affect the pharmacokinetics of CYP2C9 substrates diclofenac or tolbutamide.

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

Theoretically, ginkgo might decrease levels of drugs metabolized by CYP3A4.
There is conflicting evidence about whether ginkgo induces or inhibits CYP3A4. Ginkgo does not appear to affect hepatic CYP3A4. However, it is not known if ginkgo affects intestinal CYP3A4. Preliminary clinical research suggests that taking ginkgo does not significantly affect levels of donepezil, lopinavir, or ritonavir, which are all CYP3A4 substrates. Other clinical research also suggests ginkgo does not significantly affect CYP3A4 activity. However, there are two case reports of decreased efavirenz concentrations and increased viral load in patients taking ginkgo. It is suspected that terpenoids from the ginkgo extract reduced drug levels by inducing cytochrome P450 3A4 (CYP3A4).

Likelihood Possible Evidence B
Efavirenz (Sustiva)

Theoretically, ginkgo might decrease the levels and clinical effects of efavirenz.
There are two case reports of decreased efavirenz concentrations and increased viral load in patients taking ginkgo. In one case, an HIV-positive male experienced over a 50% decrease in efavirenz levels over the course of 14 months while taking ginkgo extract. HIV-1 RNA copies also increased substantially, from less than 50 to more than 1500. It is suspected that terpenoids from the ginkgo extract reduced drug levels by inducing cytochrome P450 3A4 (CYP3A4). In another case report, a patient stable on antiviral therapy including efavirenz for 10 years, had an increase in viral load from <50 copies/mL to 1350 copies/mL after 2 months of taking a combination of supplements including ginkgo. After stopping ginkgo, the viral load was again controlled with the same antiviral therapy regimen.

Likelihood Possible Evidence D
Ibuprofen (Advil, Others)

Theoretically, ginkgo might increase the risk of bleeding when used with ibuprofen.
Ginkgo might have antiplatelet effects and has been associated with several case reports of spontaneous bleeding. In one case, a 71-year-old male had taken a specific ginkgo extract (Gingium, Biocur) 40 mg twice daily for 2.5 years. About 4 weeks after starting ibuprofen 600 mg daily he experienced a fatal intracerebral hemorrhage. However, the antiplatelet effects of ginkgo have been questioned. A meta-analysis and other studies have not found a significant antiplatelet effect with standardized ginkgo extracts, 80 mg to 480 mg taken daily for up to 32 weeks.

Likelihood Possible Evidence D
P-Glycoprotein Substrates

Theoretically, taking ginkgo with P-glycoprotein substrates might increase the levels and adverse effects of these substrates.
A small clinical study in healthy volunteers shows that using ginkgo leaf extract 120 mg orally three times daily for 14 days can increase levels of the P-glycoprotein substrate, talinolol, by 36% in healthy male individuals. However, single doses of ginkgo do not have the same effect.

Likelihood Possible Evidence B
Risperidone (Risperdal)

Theoretically, taking ginkgo with risperidone might increase the levels and adverse effects of risperidone.
A single case of priapism has been reported for a 26-year-old male with schizophrenia who used risperidone 3 mg daily along with ginkgo extract 160 mg daily. Risperidone is metabolized by cytochrome P450 (CYP) 2D6 and CYP3A4. CYP3A4 activity might be affected by ginkgo. Theoretically, ginkgo may inhibit the metabolism of risperidone and increase the risk of adverse effects.

Likelihood Possible Evidence D
Rosiglitazone (Avandia)

Theoretically, ginkgo might decrease the levels and clinical effects of rosiglitazone.
Animal research shows that ginkgo leaf extract orally 100 or 200 mg/kg daily for 10 days alters the pharmacodynamics of rosiglitazone in a dose-dependent manner. The 100 mg/kg and 200 mg/kg doses reduce the area under the concentration time curve (AUC) of rosiglitazone by 39% and 52%, respectively, and the half-life by 28% and 39%, respectively. It is hypothesized that these changes may be due to induction of cytochrome P450 2C8 by ginkgo.

Likelihood Possible Evidence D
Seizure Threshold Lowering Drugs

Theoretically, taking ginkgo with drugs that lower the seizure threshold might increase the risk for convulsions.
Ginkgo seeds contain ginkgotoxin. Large amounts of ginkgotoxin can cause neurotoxicity and seizure. Ginkgotoxin is present in much larger amounts in ginkgo seeds than leaves. Ginkgo leaf extract contains trace amounts of ginkgotoxin. The amount of ginkgotoxin in ginkgo leaf and leaf extract seems unlikely to cause toxicity. However, there are anecdotal reports of seizure occurring after use of ginkgo leaf both in patients without a history of seizure disorder and in those with previously well-controlled epilepsy.

Likelihood Possible Evidence D
Simvastatin (Zocor)

Theoretically, ginkgo might decrease the levels and clinical effects of simvastatin.
Clinical research shows that taking ginkgo extract can reduce the area under the curve and maximum concentration of simvastatin by 32% to 39%. However, ginkgo extract does not seem to affect the cholesterol-lowering ability of simvastatin.

Likelihood Probable Evidence B
Sofosbuvir (Sovaldi)

Theoretically, ginkgo might increase the levels and clinical effects of sofosbuvir.
Animal research in rats shows that giving a ginkgo extract 25 mg/kg orally daily for 14 days increases the area under the concentration time curve (AUC) after a single sofosbuvir dose of 40 mg/kg by 11%, increases the half-life by 60%, and increases the plasma concentration at 4 hours by 38%. This interaction appears to be related to the inhibition of intestinal P-glycoprotein by ginkgo.

Likelihood Possible Evidence D
Tacrolimus (Prograf)

Theoretically, ginkgo might increase the blood levels of tacrolimus.
In vitro evidence suggests that certain biflavonoids in ginkgo leaves (i.e. amentoflavone, ginkgetin, bilobetin) may inhibit the metabolism of tacrolimus by up to 50%. This interaction appears to be time-dependent and due to inhibition of cytochrome P450 (CYP) 3A4 by these bioflavonoids. In rats given tacrolimus 1 mg/kg orally, amentoflavone was shown to increase the area under the concentration time curve (AUC) of tacrolimus by 3.8-fold.

Likelihood Possible Evidence D
Trazodone (Desyrel)

Theoretically, ginkgo might increase the levels and clinical effects of trazodone.
In a case report, an Alzheimer patient taking trazodone 20 mg twice daily and ginkgo leaf extract 80 mg twice daily for four doses became comatose. The coma was reversed by administration of flumazenil (Romazicon). Coma might have been induced by excessive GABA-ergic activity. Ginkgo flavonoids are thought to have GABA-ergic activity and act directly on benzodiazepine receptors. Ginkgo might also increase metabolism of trazodone to active GABA-ergic metabolites, possibly by inducing cytochrome P450 3A4 (CYP3A4) metabolism.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Ginkgo has been shown to increase the risk of bleeding in some people when taken with warfarin.
Several pharmacodynamic studies suggest that ginkgo inhibits platelet aggregation. It is thought that the ginkgo constituent, ginkgolide B, displaces platelet-activating factor (PAF) from its binding sites, decreasing blood coagulation. Several case reports have documented serious bleeding events in patients taking ginkgo. Information from a medical database suggests that when taken concurrently with warfarin, ginkgo increases the risk of a bleeding adverse event by 38%. There is also some evidence that ginkgo leaf extract can inhibit cytochrome P450 2C9, an enzyme that metabolizes warfarin. This could result in increased warfarin levels. However, population and clinical research has produced mixed results. Clinical research in healthy people suggests that ginkgo has no effect on INR, or the pharmacokinetics or pharmacodynamics of warfarin. A meta-analysis of 18 studies using standardized ginkgo extracts, 80 mg to 480 mg daily for up to 32 weeks, did not find a significant effect on platelet aggregation, fibrinogen concentration, or PT/aPTT. There is also some preliminary clinical research that suggests ginkgo might not significantly increase the effects of warfarin in patients that have a stable INR.

Likelihood Possible Evidence B
Nifedipine (Procardia)

Theoretically, taking ginkgo with oral, but not intravenous, nifedipine might increase levels and adverse effects of nifedipine.
Animal research and some clinical evidence suggests that taking ginkgo leaf extract orally in combination with oral nifedipine might increase nifedipine levels and cause increased side effects, such as headaches, dizziness, and hot flushes. However, taking ginkgo orally does not seem to affect the pharmacokinetics of intravenous nifedipine.

Likelihood Possible Evidence B
Omeprazole (Prilosec)

Theoretically, taking ginkgo with omeprazole might decrease the levels and clinical effects of omeprazole.
Clinical research shows that a specific ginkgo leaf extract (Remembrance, Herbs Product LTD) 140 mg twice daily can induce cytochrome P450 (CYP) 2C19 enzymes and decrease levels of omeprazole by about 27% to 42%.

Likelihood Possible Evidence B
Ginkgo biloba full monograph & interactions

American Ginseng4 drug types · 217 drugs

Warfarin (Coumadin)

American ginseng seems to decrease the effectiveness of warfarin therapy.
Healthy patients receiving warfarin 5 mg daily, who also take American ginseng 1 gram twice daily, seem to have a significantly reduced international normalized ratio (INR).

Likelihood Likely Evidence B
Antidiabetes Drugs

Theoretically, taking American ginseng with antidiabetes drugs might increase the risk of hypoglycemia.
American ginseng seems to lower postprandial blood glucose. Theoretically, concomitant use with antidiabetes drugs might enhance blood glucose lowering effects and possibly cause hypoglycemia.

Likelihood Probable Evidence B
Immunosuppressants

Theoretically, American ginseng use might interfere with immunosuppressive therapy.
American ginseng seems to stimulate immune function. Theoretically, American ginseng might decrease the effectiveness of immunosuppressant drugs.

Likelihood Possible Evidence D
Monoamine Oxidase Inhibitors (Maois)

Theoretically, American ginseng can interfere with MAOI therapy.
There is one case report of insomnia, headache, and tremors when an unspecified ginseng product was used with phenelzine (Nardil), an MAOI. There is also one case report of hypomania when an unspecified ginseng product was used with phenelzine. Theoretically, American ginseng may interfere with MAOI therapy.

Likelihood Possible Evidence D
American Ginseng full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Clear Thinking, from the product label.

Herb Stop

See all Herb Stop products
Name
The Herb Stop
Street Address
PO Box 673
City
Pine
State
AZ
ZipCode
85544
Phone Number
877.345.4372
Web Address
www.herbstop.com
Pharmacist Counseling Corner

Clear Thinking by Herb Stop: Common Questions

Does Clear Thinking by Herb Stop interact with any medications?
Yes. Based on its ingredients, Clear Thinking has a known interaction with 1,352 medications, including 3 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Clear Thinking contains 4 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.
What does ginkgo biloba do?
Ginkgo is possibly effective for several conditions: hearing loss, stroke recovery, schizophrenia, premenstrual syndrome, dementia, and anxiety. The strength of evidence varies, but these are the uses studied.
Is American ginseng safe with my diabetes medication?
American ginseng may lower blood sugar on its own, so combining it with diabetes drugs carries a Moderate-severity risk of low blood sugar. Talk to your pharmacist or doctor before adding it — they can help you watch for symptoms and adjust dosing if needed.
Can I take this if I'm pregnant?
The safety data advises against both ginkgo and American ginseng during pregnancy. Icelandic moss also has insufficient safety information for pregnancy. Talk with your doctor or pharmacist about whether this product is right for you.
What's Icelandic moss for?
We don't have effectiveness data on file for Icelandic moss. The ingredient is generally well tolerated short-term, but human evidence is limited and quality varies between products.
Can I take this while breastfeeding?
The facts advise against all three active ingredients — ginkgo, American ginseng, and Icelandic moss — while breastfeeding because there isn't enough safety data. Check with your doctor or pharmacist for personalized advice.
What's the most common side effect?
For ginkgo, dizziness and stomach upset are most common. American ginseng most often causes headache. Icelandic moss can irritate the stomach. In general, these are mild, but if you experience bleeding or heart rhythm changes, stop and contact your doctor.

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

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

Clear Thinking label
Go deeper

The Full Monographs Behind Clear Thinking’s Ingredients

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

Herb & supplement monograph

Ginkgo

Interacts with 1,266 drugs

Ginkgo is one of the world's most popular herbal supplements, mostly taken to support memory and circulation. The evidence for these uses is mixed and generally weak, and it is not proven to...

Read the full Ginkgo monograph → Herb & supplement monograph

American Ginseng

Interacts with 217 drugs

American ginseng is an herbal root used as an 'adaptogen' to support energy, stress, immune function, and blood sugar. Some uses—such as reducing the chance or length of colds and modestly l...

Read the full American Ginseng monograph → Herb & supplement monograph

Iceland Moss

Iceland moss is a lichen traditionally used as a soothing remedy for dry cough and throat or mouth irritation, mainly because of its mucilage (gel-forming fibers). High-quality human studies...

Read the full Iceland Moss monograph →
Sources

Sources & How We Checked

Clear Thinking'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 112 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.

Ginkgo 97 references
  1. Davydov L, Stirling AL. Stevens-Johnson syndrome with Ginkgo biloba. J Herb Pharmacother 2001;1:65-9. DOI
  2. Benjamin J, Muir T, Briggs K, Pentland B. A case of cerebral haemorrhage-can Ginkgo biloba be implicated? Postgrad Med J 2001;77:112-3.
  3. Matthews, MK. Association of Ginkgo biloba with intracerebral hemorrhage. Neurology 1998;50:1934.
  4. Rowin J, Lewis SL. Spontaneous bilateral subdural hemotomas with chronic Ginkgo biloba ingestion. Neurology 1996;46:1775-6.
  5. Rosenblatt M, Mindel T. Spontaneous hyphema associated with ingestion of Ginkgo biloba extract. N Engl J Med 1997;336:1108.
  6. Fessenden JM, Wittenborn W, Clarke L. Gingko biloba: a case report of herbal medicine and bleeding postoperatively from a laparoscopic cholecystectomy. Am Surg 2001;67:33-5. DOI
  7. Gurley BJ, Gardner SF, Hubbard MA. Clinical assessment of potential cytochrome P450-mediated herb-drug interactions. AAPS Ann Mtg & Expo Indianapolis, IN: 2000; Oct 29 - Nov 2:presentation #3460.
  8. Cohen AJ, Bartlik B. Ginkgo biloba for antidepressant-induced sexual dysfunction. J Sex Marital Ther 1998;24:139-43. PubMed
  9. Kudolo GB. The effect of 3-month ingestion of Ginkgo biloba extract on pancreatic beta-cell function in response to glucose loading in normal glucose tolerant individuals. J Clin Pharmacol 2000;40:647-54.
  10. Heck AM, DeWitt BA, Lukes AL. Potential interactions between alternative therapies and warfarin. Am J Health Syst Pharm 2000;57:1221-7. DOI
  11. Cesarani A, Meloni F, Alpini D, et al. Ginkgo biloba (EGb 761) in the treatment of equilibrium disorders. Adv Ther 1998;15:291-304.
  12. Galluzzi S, Zanetti O, Binetti G, et al. Coma in a patient with Alzheimer's disease taking low dose trazodone and Ginkgo biloba. J Neurol Neurosurg Psychiatry 2000;68:679-80. DOI
  13. Budzinski JW, Foster BC, Vandenhoek S, Arnason JT. An in vitro evaluation of human cytochrome P450 3A4 inhibition by selected commercial herbal extracts and tinctures. Phytomedicine 2000;7:273-82. PubMed
  14. Gregory PJ. Seizure associated with Ginkgo biloba? Ann Intern Med 2001;134:344.
  15. Granger AS. Ginkgo biloba precipitating epileptic seizures. Age Ageing 2001;30:523-5. PubMed
  16. Kajiyama Y, Fujii K, Takeuchi H, Manabe Y. Ginkgo seed poisoning. Pediatrics 2002;109:325-7. PubMed
  17. Miwa H, Iijima M, Tanaka S, Mizuno Y. Generalized convulsions after consuming a large amount of gingko nuts. Epilepsia 2001;42:280-1. DOI
  18. Burschka MA, Hassan HA, Reineke T, et al. Effect of treatment with Ginkgo biloba extract EGb 761 (oral) on unilateral idiopathic sudden hearing loss in a prospective randomized double-blind study of 106 outpatients. Eur Arch Otorhinolaryngol 2001;258:213- PubMed
  19. Miller LG, Freeman B. Possible subdural hematoma associated with Ginkgo biloba. J Herb Pharmacother 2002;2:57-63.
  20. Kudolo GB, Dorsey S, Blodgett J. Effect of the ingestion of Ginkgo biloba extract on platelet aggregation and urinary prostanoid excretion in healthy and Type 2 diabetic subjects. Thromb Res 2002;108:151-60.. PubMed
  21. Fong KC, Kinnear PE. Retrobulbar haemorrhage associated with chronic Ginkgo biloba ingestion. Postgrad Med J 2003;79:531-2..
  22. Gurley BJ, Gardner SF, Hubbard MA, et al. Cytochrome P450 phenotypic ratios for predicting herb-drug interactions in humans. Clin Pharmacol Ther 2002;72:276-87.. PubMed
  23. Kang BJ, Lee SJ, Kim MD, Cho MJ. A placebo-controlled, double-blind trial of Ginkgo biloba for antidepressant-induced sexual dysfunction. Hum Psychopharmacol 2002;17:279-84.
  24. Yale SH, Glurich I. Analysis of the inhibitory potential of Ginkgo biloba, Echinacea purpurea, and Serenoa repens on the metabolic activity of cytochrome P450 3A4, 2D6, and 2C9. J Altern Complement Med 2005;11:433-9.
  25. Yasui-Furukori N, Furukori H, Kaneda A, et al. The effects of Ginkgo biloba extracts on the pharmacokinetics and pharmacodynamics of donepezil. J Clin Pharmacol 2004;44:538-42.
  26. Markowitz JS, Donovan JL, Lindsay DeVane C, et al. Multiple-dose administration of Ginkgo biloba did not affect cytochrome P-450 2D6 or 3A4 activity in normal volunteers. J Clin Psychopharmacol 2003;23:576-81. PubMed
  27. Arenz A, Kelin M, Flehe K, et al. Occurrence of neurotoxic 4'-O-methylpyridoxine in ginkgo biloba leaves, ginkgo medications and Japanese ginkgo food. Planta Med 1996;62:548-51.
  28. Engelsen J, Nielsen JD, Winther K. Effect of coenzyme Q10 and Ginkgo biloba on warfarin dosage in stable, long-term warfarin treated outpatients. A randomised, double blind, placebo-crossover trial. Thromb Haemost 2002;87:1075-6. DOI
  29. Gaudineau C, Beckerman R, Welbourn S, Auclair K. Inhibition of human P450 enzymes by multiple constituents of the Ginkgo biloba extract. Biochem Biophys Res Comm 2004;318:1072–8. PubMed
  30. Kohler S, Funk P, Kieser M. Influence of a 7-day treatment with Ginkgo biloba special extract EGb 761 on bleeding time and coagulation: a randomized, placebo-controlled, double-blind study in healthy volunteers. Blood Coagul Fibrinolysis 2004;15:303–9. PubMed
  31. Jiang X, Williams KM, Liauw WS, et al. Effect of ginkgo and ginger on the pharmacokinetics and pharmacodynamics of warfarin in healthy subjects. Br J Clin Pharmacol 2005;59:425-32. PubMed
  32. Destro MW, Speranzini MB, Cavalheiro Filho C, et al. Bilateral haematoma after rhytidoplasty and blepharoplasty following chronic use of Ginkgo biloba. Br J Plast Surg 2005;58:100-1. PubMed
  33. Yin OQ, Tomlinson B, Waye MM, et al. Pharmacogenetics and herb-drug interactions: experience with Ginkgo biloba and omeprazole. Pharmacogenetics 2004;14:841-50. PubMed
  34. Bent S, Goldberg H, Padula A, Avins AL. Spontaneous bleeding associated with Ginkgo biloba: a case report and systematic review of the literature. J Gen Intern Med 2005;20;657-61. DOI
  35. Meisel C, Johne A, Roots I. Fatal intracerebral mass bleeding associated with Ginkgo biloba and ibuprofen. Atherosclerosis 2003;167:367. PubMed
  36. Bebbington A, Kulkarni R, Roberts P. Ginkgo biloba: Persistent bleeding after total hip arthroplasty caused by herbal self-medication. J Arthroplasty 2005;20:125-6. .
  37. Kupiec T, Raj V. Fatal seizures due to potential herb-drug interactions with Ginkgo biloba. J Anal Toxicol 2005:755-8. PubMed
  38. Hauser D, Gayowski T, Singh N. Bleeding complications precipitated by unrecognized Gingko biloba use after liver transplantation. Transpl Int 2002;15:377-9. DOI
  39. Mohutsky MA, Anderson GD, Miller JW, Elmer GW. Ginkgo biloba: evaluation of CYP2C9 drug interactions in vitro and in vivo. Am J Ther 2006;13:24-31. PubMed
  40. Kudolo GB. The effect of 3-month ingestion of Ginkgo biloba extract (EGb 761) on pancreatic beta-cell function in response to glucose loading in individuals with non-insulin-dependent diabetes mellitus. J Clin Pharmacol 2001;41:600-11.
  41. Pennisi RS. Acute generalised exanthematous pustulosis induced by the herbal remedy Ginkgo biloba. Med J Aust 2006;184:583-4. PubMed
  42. Yagmur E, Piatkowski A, Groger A, et al. Bleeding complication under Gingko biloba medication. Am J Hematol 2005;79:343-4. PubMed
  43. Vale S. Subarachnoid haemorrhage associated with Ginkgo biloba. Lancet 1998;352:36. PubMed
  44. Aruna D, Naidu MU. Pharmacodynamic interaction studies of Ginkgo biloba with cilostazol and clopidogrel in healthy human subjects. Br J Clin Pharmacol 2007;63:333-8.
  45. Dugoua JJ, Mills E, Perri D, Koren G. Safety and efficacy of ginkgo (Ginkgo biloba) during pregnancy and lactation. Can J Clin Pharmacol 2006;13:e277-84.
  46. Jiang X, Blair EY, McLachlan AJ. Investigation of the effects of herbal medicines on warfarin response in healthy subjects: a population pharmacokinetic-pharmacodynamic modeling approach. J Clin Pharmacol 2006;46:1370-8. PubMed
  47. Woelk H, Arnoldt KH, Kieser M, Hoerr R. Ginkgo biloba special extract EGb 761 in generalized anxiety disorder and adjustment disorder with anxious mood: a randomized, double-blind, placebo-controlled trial. J Psychiatr Res 2007;41:472-80. PubMed
  48. DeKosky ST, Williamson JD, Fitzpatrick AL, et al. Ginkgo biloba for prevention of dementia. JAMA 2008;300:2253-62.
  49. Dodge HH, Zitzelberger T, Oken BS, et al. A randomized placebo-controlled trial of ginkgo biloba for the prevention of cognitive decline. Neurology 2008;70(19 Pt 2):1809-17. PubMed
  50. Wiegman DJ, Brinkman K, Franssen EJ. Interaction of Ginkgo biloba with efavirenz. AIDS 2009;23:1184-5. PubMed
  51. Kim BH, Kim KP, Lim KS, et al. Influence of Ginkgo biloba extract on the pharmacodynamic effects and pharmacokinetic properties of ticlopidine: An open-label, randomized, two-period, two-treatment, two-sequence, single-dose crossover study in healthy Kor
  52. Salehi B, Imani R, Mohammadi MR, et al. Ginkgo biloba for attention-deficit/hyperactivity disorder in children and adolescents: a double blind, randomized controlled trial. Prog Neuropsychopharmacol Biol Psychiatry 2010;34:76-80. PubMed
  53. Kellermann AJ, Kloft C. Is there a risk of bleeding associated with standardized ginkgo biloba extract therapy? A systematic review and meta-analysis. Pharmacotherapy 2011;31:490-502.
  54. Kuller LH, Ives DG, Fitzpatrick AL, et al. Does Ginkgo biloba reduce the risk of cardiovascular events? Circ Cardiovasc Qual Outcomes 2010;3:41-7.
  55. Naccarato M, Yoong D, Gough K. A potential drug-herbal interaction between Ginkgo biloba and efavirenz. J Int Assoc Physicians AIDS Care (Chic). 2012;11(2):98-100. doi: 10.1177/1545109711435364. Epub 2012 Feb 9.
  56. Engelsen, J., Nielsen, J. D., and Hansen, K. F. [Effect of Coenzyme Q10 and Ginkgo biloba on warfarin dosage in patients on long-term warfarin treatment. A randomized, double-blind, placebo-controlled cross-over trial]. Ugeskr.Laeger 4-28-2003;165(18):18
  57. Parsad, D., Pandhi, R., and Juneja, A. Effectiveness of oral Ginkgo biloba in treating limited, slowly spreading vitiligo. Clin Exp.Dermatol. 2003;28(3):285-287.
  58. Bal Dit, Sollier C., Caplain, H., and Drouet, L. No alteration in platelet function or coagulation induced by EGb761 in a controlled study. Clin Lab Haematol. 2003;25(4):251-253. PubMed
  59. Yoshioka, M., Ohnishi, N., Koishi, T., Obata, Y., Nakagawa, M., Matsumoto, T., Tagagi, K., Takara, K., Ohkuni, T., Yokoyama, T., and Kuroda, K. Studies on interactions between functional foods or dietary supplements and medicines. IV. Effects of ginkgo b
  60. Yoshioka, M., Ohnishi, N., Sone, N., Egami, S., Takara, K., Yokoyama, T., and Kuroda, K. Studies on interactions between functional foods or dietary supplements and medicines. III. Effects of ginkgo biloba leaf extract on the pharmacokinetics of nifedipi
  61. Lovera, J., Bagert, B., Smoot, K., Morris, C. D., Frank, R., Bogardus, K., Wild, K., Oken, B., Whitham, R., and Bourdette, D. Ginkgo biloba for the improvement of cognitive performance in multiple sclerosis: a randomized, placebo-controlled trial. Mult.S PubMed
  62. Lin, Y. Y., Chu, S. J., and Tsai, S. H. Association between priapism and concurrent use of risperidone and Ginkgo biloba. Mayo Clin Proc 2007;82(10):1289-1290.
  63. Robertson, S. M., Davey, R. T., Voell, J., Formentini, E., Alfaro, R. M., and Penzak, S. R. Effect of Ginkgo biloba extract on lopinavir, midazolam and fexofenadine pharmacokinetics in healthy subjects. Curr Med Res Opin 2008;24(2):591-599. PubMed
  64. Penzak, S. R., Busse, K. H., Robertson, S. M., Formentini, E., Alfaro, R. M., and Davey, R. T., Jr. Limitations of using a single postdose midazolam concentration to predict CYP3A-mediated drug interactions. J Clin Pharmacol 2008;48(6):671-680. PubMed
  65. May, B. H., Yang, A. W., Zhang, A. L., Owens, M. D., Bennett, L., Head, R., Cobiac, L., Li, C. G., Hugel, H., Story, D. F., and Xue, C. C. Chinese herbal medicine for Mild Cognitive Impairment and Age Associated Memory Impairment: a review of randomised
  66. Choi, W. S., Choi, C. J., Kim, K. S., Lee, J. H., Song, C. H., Chung, J. H., Ock, S. M., Lee, J. B., and Kim, C. M. To compare the efficacy and safety of nifedipine sustained release with Ginkgo biloba extract to treat patients with primary Raynaud's phe
  67. Lei, H. P., Wang, G., Wang, L. S., Ou-yang, D. S., Chen, H., Li, Q., Zhang, W., Tan, Z. R., Fan, L., He, Y. J., and Zhou, H. H. Lack of effect of Ginkgo biloba on voriconazole pharmacokinetics in Chinese volunteers identified as CYP2C19 poor and extensiv
  68. Russo, V., Stella, A., Appezzati, L., Barone, A., Stagni, E., Roszkowska, A., and Delle, Noci N. Clinical efficacy of a Ginkgo biloba extract in the topical treatment of allergic conjunctivitis. Eur J Ophthalmol. 2009;19(3):331-336. PubMed
  69. Fan, L., Tao, G. Y., Wang, G., Chen, Y., Zhang, W., He, Y. J., Li, Q., Lei, H. P., Jiang, F., Hu, D. L., Huang, Y. F., and Zhou, H. H. Effects of Ginkgo biloba extract ingestion on the pharmacokinetics of talinolol in healthy Chinese volunteers. Ann Phar PubMed
  70. Ozgoli, G., Selselei, E. A., Mojab, F., and Majd, H. A. A randomized, placebo-controlled trial of Ginkgo biloba L. in treatment of premenstrual syndrome. J Altern.Complement Med 2009;15(8):845-851.
  71. Singh, V., Singh, S. P., and Chan, K. Review and meta-analysis of usage of ginkgo as an adjunct therapy in chronic schizophrenia. Int J Neuropsychopharmacol. 2010;13(2):257-271.
  72. Kim, T. E., Kim, B. H., Kim, J., Kim, K. P., Yi, S., Shin, H. S., Lee, Y. O., Lee, K. H., Shin, S. G., Jang, I. J., and Yu, K. S. Comparison of the pharmacokinetics of ticlopidine between administration of a combined fixed-dose tablet formulation of ticl
  73. Nicolai, S. P., Gerardu, V. C., Kruidenier, L. M., Prins, M. H., and Teijink, J. A. From the Cochrane library: Ginkgo biloba for intermittent claudication. Vasa 2010;39(2):153-158. PubMed
  74. Patel, N. Herbal remedies. Br.Dent.J 8-28-2010;209(4):153.
  75. Pedroso, J. L., Henriques Aquino, C. C., Escorcio Bezerra, M. L., Baiense, R. F., Suarez, M. M., Dutra, L. A., Braga-Neto, P., and Povoas Barsottini, O. G. Ginkgo biloba and cerebral bleeding: a case report and critical review. Neurologist. 2011;17(2):89 PubMed
  76. Russo, V., Rago, A., Russo, G. M., Calabro, R., and Nigro, G. Ginkgo biloba: an ancient tree with new arrhythmic side effects. J Postgrad.Med 2011;57(3):221.
  77. Zhou, Y. and Zeng, R. [Effects of Ginkgo biloba extract on anticoagulation and blood drug level of warfarin in healthy wolunteers]. Zhongguo Zhong Yao Za Zhi 2011;36(16):2290-2293. DOI
  78. Skogh, M. Extracts of Ginkgo biloba and bleeding or haemorrhage. Lancet 10-3-1998;352(9134):1145-1146. PubMed
  79. Fessenden JM, Wittenborn W, and Clarke L. Ginkgo biloba: a case report of herbal medicine and bleeding postoperatively from a laparoscopic cholecystectomy. Am Surg 2001;67(1):33-35.
  80. Burkard G. [The efficacy and safety of ginkgo biloba extract in dementia]. Fortschr Med [Supp] 1991;109(107):6-8.
  81. Dai LL, Fan L, Wu HZ, Tan ZR, Chen Y, Peng XD, Shen MX, Yang GP, Zhou HH. Assessment of a pharmacokinetic and pharmacodynamic interaction between simvastatin and Ginkgo biloba extracts in healthy subjects. Xenobiotica 2013;43(10):862-7.
  82. Guo CX, Pei Q, Yin JY, Peng XD, Zhou BT, Zhao YC, Wu LX, Meng XG, Wang G, Li Q, Ouyang DS, Liu ZQ, Zhang W, Zhou HH. Effects of Ginkgo biloba extracts on pharmacokinetics and efficacy of atorvastatin based on plasma indices. Xenobiotica 2012;42(8):784-90.
  83. Stoddard GJ, Archer M, Shane-McWhorter L, Bray BE, Redd DF, Proulx J, Zeng-Treitler Q. Ginkgo and Warfarin Interaction in a Large Veterans Administration Population. AMIA Annu Symp Proc. 2015 Nov 5;2015:1174-83.
  84. Jalloh MA, Gregory PJ, Hein D, et al. Dietary supplement interactions with antiretrovirals: a systematic review. Int J STD AIDS. 2017 Jan;28(1):4-15. PubMed
  85. Carlile PV. Unexplained alveolar hemorrhage associated with ginkgo and ginseng use. J Bronchology Interv Pulmonol. 2015;22(2):170-2. doi: 10.1097/LBR.0000000000000150. PubMed
  86. Han EJ, Park HL, Kim SH. Allergic Reaction to Ginkgo Nut on FDG PET/CT. Clin Nucl Med. 2016 Sep;41(9):716-7. doi: 10.1097/RLU.0000000000001276. PubMed
  87. Rho SS, Woo YS, Bahk WM. Ginkgo biloba induced mood dysregulation: a case report. BMC Complement Altern Med. 2018 Jan 15;18(1):14. PubMed
  88. Aziz TA, Hussain SA, Mahwi TO, Ahmed ZA, Rahman HS, Rasedee A. The efficacy and safety of Ginkgo biloba extract as an adjuvant in type 2 diabetes mellitus patients ineffectively managed with metformin: a double-blind, randomized, placebo-controlled trial.
  89. World Health Organization. WHO pharmaceuticals newsletter: 2020, No. 3. Available at: https://www.who.int/medicines/publications/WHO_Pharmaceuticals_Newslet3_20.pdf?ua=1. Accessed June 23, 2021.
  90. Health Canada. Ginkgo biloba-containing products and the risk of cardiac arrhythmias. Health Product InfoWatch. February 2021. Available at: https://www.canada.ca/en/health-canada/services/drugs-health-products/medeffect-canada/health-product-infowatch/fe
  91. Wasef AK, Wahdan SA, Saeed NM, El-Demerdash E. Effects of aged garlic and ginkgo biloba extracts on the pharmacokinetics of sofosbuvir in rats. Biopharm Drug Dispos. 2022;43(4):152-62. PubMed
  92. Xing X, Kong M, Hou Q, Li J, Qian W, Chen X, Li H, Yang C. Effects of ginkgo leaf tablet on the pharmacokinetics of rosiglitazone in rats and its potential mechanism. Pharm Biol. 2022;60(1):1190-7. PubMed
  93. Hoerr R, Zimmermann A, Seitz F, Dienel A. Single and repeated doses of EGb 761® do not affect pharmacokinetics or pharmacodynamics of rivaroxaban in healthy subjects. Front Pharmacol. 2022 Apr 20;13:868843. PubMed
  94. Bai J, Zhang C. Metabolic interaction between biflavonoids in Ginkgo biloba leaves and tacrolimus. Biopharm Drug Dispos 2023;44(2):157-164.
  95. Wang Q, Liu Z, Wang R, et al. Effect of Ginkgo biloba extract on pharmacology and pharmacokinetics of atorvastatin in rats with hyperlipidaemia. Food Funct 2023;14(7):3051-3066.
  96. Burnett CL, Bergfeld WF, Belsito DV, et al. Safety Assessment of Ginkgo biloba-Derived Ingredients as Used in Cosmetics. Int J Toxicol. 2023 Nov 6:10915818231210792.
  97. Yao Y, Zhao J, Li C, et al. Ginkgo biloba extract safety: Insights from a real-world pharmacovigilance study of FDA adverse event reporting system (FAERS) events. J Ethnopharmacol 2025;337(Pt 3):119010. PubMed

See these in context on the Ginkgo monograph →

American Ginseng 12 references
  1. Shader RI, Greenblatt DJ. Phenelzine and the dream machine-ramblings and reflections. J Clin Psychopharmacol 1985;5:65. PubMed
  2. Jones BD, Runikis AM. Interaction of ginseng with phenelzine. J Clin Psychopharmacol 1987;7:201-2. PubMed
  3. Janetzky K, Morreale AP. Probable interaction between warfarin and ginseng. Am J Health Syst Pharm 1997;54:692-3. PubMed
  4. Vuksan V, Sievenpiper JL, Koo VY, et al. American ginseng (Panax quinquefolius L) reduces postprandial glycemia in nondiabetic subjects and subjects with type 2 diabetes mellitus. Arch Intern Med 2000;160:1009-13. PubMed
  5. Vuksan V, Stavro MP, Sievenpiper JL, et al. Similar postprandial glycemic reductions with escalation of dose and administration time of American ginseng in type 2 diabetes. Diabetes Care 2000;23:1221-6. PubMed
  6. Chan LY, Chiu PY, Lau TK. An in-vitro study of ginsenoside Rb(1)-induced teratogenicity using a whole rat embryo culture model. Hum Reprod 2003;18:2166-8..
  7. McElhaney JE, Gravenstein S, Cole SK, et al. A Placebo-Controlled Trial of a Proprietary Extract of North American Ginseng (CVT-E002) to Prevent Acute Respiratory Illness in Institutionalized Older Adults. J Am Geriatr Soc 2004;52:13-9. PubMed
  8. Yuan CS, Wei G, Dey L, et al. American ginseng reduces warfarin's effect in healthy patients: a randomized, controlled trial. Ann Intern Med 2004;141:23-7.
  9. Predy GN, Goel V, Lovlin R, et al. Efficacy of an extract of North American ginseng containing poly-furanosyl-pyranosyl-saccharides for preventing upper respiratory tract infections: a randomized controlled trial. CMAJ 2005;173:1043-8.. PubMed
  10. McElhaney JE, Goel V, Toane B, et al. Efficacy of COLD-fX in the prevention of respiratory symptoms in community-dwelling adults: a randomized, double-blinded, placebo controlled trial. J Altern Complement Med 2006;12:153-7. PubMed
  11. Predy GN, Goel V, Lovlin RE, et al. Immune modulating effects of daily supplementation of COLD-fX (a proprietary extract of North American ginseng) in healthy adults. J Clin Biochem Nutr 2006;39:162-167. DOI
  12. Stavro PM, Woo M, Leiter LA, et al. Long-term intake of North American ginseng has no effect on 24-hour blood pressure and renal function. Hypertension 2006;47(4):791-6. PubMed

See these in context on the American Ginseng monograph →

Iceland Moss 3 references
  1. Tyler VE. Herbs of Choice. Binghamton, NY: Pharmaceutical Products Press, 1994.
  2. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  3. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.

See these in context on the Iceland Moss monograph →

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

© 2021 Therapeutic Research Center, LLC

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