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Dietary supplement

Cogni-Flex Ingredients & Drug Interactions

by Douglas Laboratories

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

First and foremost: checking Cogni-Flex 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

Cogni-Flex is a dietary supplement by Douglas Laboratories with 4 active ingredients. Its ingredients are commonly taken for memory and cognitive support, alzheimer's disease and dementia, age-related memory decline.Based on those ingredients, 1,415 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Ginkgo biloba, Huperzine A, Phosphatidylserine. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Cogni-Flex by Douglas Laboratories

Ask about any prescription or over-the-counter medication and we check it for interactions with Cogni-Flex by Douglas Laboratories — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Cogni-Flex by Douglas Laboratories

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

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 4 of its 4 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

Cogni-Flex contains four active ingredients. Huperzine A is a compound that works by blocking an enzyme that breaks down acetylcholine, a chemical messenger in the brain—it's been studied mainly for Alzheimer disease.

Acetyl-L-carnitine is a form of the amino acid carnitine, which may support brain energy and mood. Phosphatidylserine is a fat-like substance naturally found in cell membranes; it's also thought to affect acetylcholine.

Ginkgo biloba is an herb extract traditionally used to support blood flow and mental clarity. The capsule also contains inactive ingredients: microcrystalline cellulose (a filler), gelatin (the capsule shell), vegetable stearate (a lubricant), and silica.

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, Alzheimer disease, Attention deficit-hyperactivity disorder (ADHD), Cognitive function, Cognitive impairment, Dementia — and 4 related terms.
  • The strongest evidence on file: Ginkgo is rated "Possibly Effective" for Dementia (Natural Medicines).
  • Also on file: Huperzine A is rated "Possibly Effective" for Alzheimer disease.
  • Also on file: Acetyl-l-carnitine is rated "Possibly Effective" for Age-related cognitive decline, Alzheimer disease.

The evidence for cognitive support varies by ingredient. Huperzine A is possibly effective for Alzheimer disease specifically, but for memory, cognitive impairment, athletic performance, depression, and vascular dementia, the evidence isn't established enough to rate.

Acetyl-L-carnitine is possibly effective for age-related cognitive decline, Alzheimer disease, depression, alcohol use disorder, and diabetic neuropathy. Phosphatidylserine is possibly effective for age-related cognitive decline and Alzheimer disease, though evidence for cognitive function, dementia, ADHD, and athletic performance is not yet established.

Ginkgo biloba is possibly effective for dementia, anxiety, hearing loss, stroke, schizophrenia, and premenstrual syndrome. Overall, the most solid support exists for Alzheimer disease and age-related decline, but this product's real-world benefit for you depends on your individual situation.

The evidence, ingredient by ingredient Huperzine A Acetyl-l-carnitine Phosphatidylserine Ginkgo

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.

Orally, huperzine A and ginkgo leaf extract are generally well tolerated, and acetyl-L-carnitine is generally well tolerated in the short term—though long-term safety for acetyl-L-carnitine and phosphatidylserine is not fully established. All four ingredients can cause side effects: huperzine A may bring on cholinergic effects like blurred vision, nausea, diarrhea, dizziness, and constipation, and in rare cases has been linked to decreased heart rate.

Acetyl-L-carnitine may cause agitation, dry mouth, headache, insomnia, loss of appetite, nausea, and diarrhea. Phosphatidylserine may cause flatulence, nausea, headache, or insomnia (especially at higher doses).

Ginkgo may cause dizziness and gastrointestinal upset, and has been associated with bleeding and, rarely, heart rhythm problems. Huperzine A should be avoided during pregnancy (not enough safety data) and while breastfeeding.

Acetyl-L-carnitine should be avoided unless your doctor advises otherwise due to insufficient safety data; breastfeeding is not recommended. Phosphatidylserine should be avoided in pregnancy and while breastfeeding.

Ginkgo is rated possibly unsafe in pregnancy (some bleeding risk) and should not be used while breastfeeding.

Side effects, ingredient by ingredient Huperzine A Acetyl-l-carnitine Phosphatidylserine Ginkgo

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 — Ginkgo, Huperzine A, Acetyl-l-carnitine, Phosphatidylserine.
  • 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: 1,416 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 Cogni-Flex, double-check if you use talinolol (a Major interaction with ginkgo). Check too for anticoagulants or blood thinners like warfarin or acenocoumarol, anticholinergic drugs (urinary or muscle-spasm medications), cholinergic drugs, serotonergic antidepressants and mood medications, thyroid hormone replacement, anxiety medications like alprazolam, cholesterol-lowering statins, HIV medications, diabetes drugs, heart or transplant immunosuppressants, or trazodone (an antidepressant)—all carry Moderate interactions with one or more of these ingredients.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with some supporting evidence for its stated purpose. Major medication interactions have been identified, and safety information is well characterized.

Cogni-Flex may be worth considering if you're interested in brain health support, especially for age-related cognitive changes or early Alzheimer disease—but the evidence is strongest for one ingredient (huperzine A) and mixed for the others. If you take any prescription medications, a blood thinner, an antidepressant, thyroid medication, or diabetes or anxiety drugs, talk to your pharmacist before starting this product.

It's not suitable if you're pregnant or breastfeeding.

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

Assessment coverage: 4 of 4 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Aug 23, 2020.

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 Cogni-Flex, straight from the product label.

Brand Douglas Laboratories
Barcode (UPC) 310539009031
Net contents 60 Capsule(s)
Market status On market
Date entered into DSLD Aug 23, 2020
DSLD ID 232026
Product type Other Combinations
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten 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 Cogni-Flex by Douglas Laboratories, 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)
Servings per container
60
UPC/BARCODE
310539009031
IngredientAmount% DV
Huperzine A100 mcg--
Acetyl-L-Carnitine HCl10 mg--
Phosphatidylserine10 mg--
Ginkgo biloba20 mg--

Other ingredients: Microcrystalline Cellulose, Gelatin, Vegetable Stearate, Silica

Tap any ingredient to jump to its full detail below.

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

Suggested Usage: Adults take 1 capsule daily or as directed by a health professional.

Precautions

Warning: If you are pregnant, nursing, have any health condition or taking any medication, consult your health professional before using this product.

Keep out of the reach of children.

Use only if safety seal is intact.

Contains: Soy

Storage

Store in a cool, dry place.

Formulation

Gluten-free, Non-GMO

Cognitive and neurological health

FDA Disclaimer Statement

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

General Statements

Scan to learn about our manufacturing excellence Contents may not fill package in order to accommodate required labeling. Please rely on stated quantity.

FDA Statement of Identity

Dietary Supplement

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

See for yourself

Cogni-Flex by Douglas Laboratories label

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

Cogni-Flex 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 Cogni-Flex by Douglas Laboratories

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 container60 Amounts shown are per serving.

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

Huperzine A

Interacts with
219 drugs
100 mcg per serving

Huperzine A is a purified compound from a Chinese clubmoss that acts like a mild cholinesterase inhibitor, similar in mechanism to some prescription A...

Huperzine A monograph & interactions

Acetyl-L-Carnitine HCl

Interacts with
203 drugs
10 mg per serving

Acetyl-L-carnitine is a form of the amino acid carnitine that the body uses to help produce energy in cells. It is most studied for nerve pain and mem...

Acetyl-L-Carnitine HCl monograph & interactions

Phosphatidylserine

Interacts with
219 drugs
10 mg per serving Form: Soy

Phosphatidylserine is a natural fat-like compound found in cell membranes, especially in the brain, and it is sold mainly to support memory and thinki...

Phosphatidylserine monograph & interactions

Ginkgo biloba

Interacts with
1,266 drugs
20 mg per serving Form: Ginkgo Flavon Glycosides, Terpene Lactones

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...

Ginkgo biloba monograph & interactions

Other (inactive) ingredients: Microcrystalline Cellulose, Gelatin, Vegetable Stearate, Silica. These complete the product’s ingredient list but are not active constituents.

Interaction report

Cogni-Flex by Douglas Laboratories Drug Interactions

Want to check YOUR meds against Cogni-Flex?

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
1,415Drugs
1 Major 1,414 Moderate

Ingredients driving the most interactions

Ginkgo biloba 1,266
Huperzine A 219
Phosphatidylserine 219
Acetyl-L-Carnitine HCl 203

Individual Drug Interactions

The ingredients in Cogni-Flex interact with 1,415 drugs. Click any drug to see the details.

4 of the 4 ingredients in Cogni-Flex interact with drugs. Each result below shows which ingredient is responsible. Ginkgo biloba Huperzine A Phosphatidylserine Acetyl-L-Carnitine HCl

Each ingredient & the kinds of drugs it affects

For each ingredient in Cogni-Flex 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

Huperzine A2 drug types · 219 drugs

Anticholinergic Drugs

Theoretically, huperzine A might decrease the effects of anticholinergic drugs.
Huperzine A has acetylcholinesterase (AChE) inhibiting effects. In animal models, huperzine A reversed cognitive deficits induced by scopolamine, an anticholinergic drug.

Likelihood Possible Evidence D
Cholinergic Drugs

Theoretically, concurrent use of huperzine A with cholinergic drugs might increase the effects and side effects of these medications.
Huperzine A can inhibit acetylcholinesterase (AChE) and might cause cumulative effects if used with cholinergic drugs.

Likelihood Possible Evidence B
Huperzine A full monograph & interactions

Phosphatidylserine2 drug types · 219 drugs

Anticholinergic Drugs

Theoretically, phosphatidylserine might decrease the effectiveness anticholinergic drugs.
Phosphatidylserine is thought to increase acetylcholine levels, which could theoretically interfere with the activity of anticholinergic agents.

Likelihood Possible Evidence B
Cholinergic Drugs

Theoretically, phosphatidylserine might have additive effects with cholinergic drugs.
Phosphatidylserine is thought to increase acetylcholine levels, which could theoretically lead to additive cholinergic effects when used with cholinergic drugs.

Likelihood Possible Evidence B
Phosphatidylserine full monograph & interactions

Acetyl-L-Carnitine HCl4 drug types · 203 drugs

Acenocoumarol (Sintrom)

Theoretically, acetyl-L-carnitine might increase the anticoagulant effects of acenocoumarol.
L-carnitine, the parent compound of acetyl-L-carnitine, might enhance the anticoagulant effects of acenocoumarol, an oral anticoagulant that is similar to warfarin, but shorter-acting. There are at least two case reports of INR elevation when L-carnitine was taken with acenocoumarol. In one case, a 33-year-old male with a previously stable INR had an elevated INR of 4.65 after L-carnitine was started and continued for 10 weeks. INR normalized after discontinuation of the L-carnitine-containing product. It is unclear if such an interaction would also occur with acetyl-L-carnitine.

Likelihood Possible Evidence D
Serotonergic Drugs

Theoretically, acetyl-L-carnitine might increase the risk of serotonergic side effects, including serotonin syndrome and cerebral vasoconstrictive disorders, when taken with serotonergic drugs.
Animal research shows that acetyl-L-carnitine can increase levels of serotonin in the brain.

Likelihood Possible Evidence D
Thyroid Hormone

Theoretically, acetyl-L-carnitine might decrease the effectiveness of thyroid hormone replacement.
L-carnitine appears to act as a peripheral thyroid hormone antagonist by inhibiting entry of thyroid hormone into the nucleus of cells. Taking L-carnitine also seems to diminish some of the symptoms of hyperthyroidism. It is unclear if such an interaction would occur with acetyl-L-carnitine.

Likelihood Probable Evidence B
Warfarin (Coumadin)

Theoretically, acetyl-L-carnitine might increase the anticoagulant effects of warfarin.
L-carnitine, the parent compound of acetyl-L-carnitine, might increase the anticoagulant effects of acenocoumarol, a shorter-acting oral anticoagulant similar to warfarin. There is not enough information to know whether this interaction occurs with acetyl-L-carnitine and warfarin.

Likelihood Possible Evidence D
Acetyl-L-Carnitine HCl full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Cogni-Flex, from the product label.

Douglas Laboratories

See all Douglas Laboratories products
Name
Douglas Laboratories
Street Address
600 Boyce Road
City
Pittsburgh
State
PA
ZipCode
15205
Phone Number
1.800.245.4440
Web Address
www.douglaslabs.com
Pharmacist Counseling Corner

Cogni-Flex by Douglas Laboratories: Common Questions

Does Cogni-Flex by Douglas Laboratories interact with any medications?
Yes. Based on its ingredients, Cogni-Flex has a known interaction with 1,415 medications, including 1 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Cogni-Flex 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.
Will Cogni-Flex work for memory and brain fog?
Huperzine A has possibly effective evidence specifically for Alzheimer disease, but for everyday memory and cognitive function, the evidence isn't yet established in the data we hold. Acetyl-L-carnitine and phosphatidylserine show possibly effective evidence for age-related cognitive decline, and ginkgo for dementia. Your results will depend on your individual situation—chat with your pharmacist about whether this blend fits your goals.
What are the most common side effects I might notice?
The most likely side effects are nausea, diarrhea, constipation, headache, insomnia, dizziness, or dry mouth. Huperzine A and the cholinergic effects of the blend may cause blurred vision. If you notice agitation, sweating, or vomiting, especially early on, let your pharmacist know right away.
Can I take Cogni-Flex while pregnant or nursing?
No—there isn't enough safety data to recommend this product during pregnancy or while breastfeeding. Talk to your OB or midwife about what might be safer for you and your baby.
Does this product have any fillers or additives I should know about?
The capsule contains microcrystalline cellulose (a filler), gelatin (the capsule shell), vegetable stearate (a lubricant), and silica. These are common inactive ingredients in supplements.
Is ginkgo in here going to cause bleeding if I take it with my blood thinner?
Ginkgo can increase bleeding risk when used with warfarin or similar anticoagulants—that's a documented Moderate interaction. Don't take Cogni-Flex with blood thinners unless your doctor or pharmacist has cleared it for you specifically.
How long do I need to take it to see results?
The product facts don't specify how long it takes for these ingredients to show effects. That timeline varies by person and by what you're hoping to achieve—your pharmacist can give you a better sense based on your situation.

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.

Cogni-Flex label
Go deeper

The Full Monographs Behind Cogni-Flex’s Ingredients

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

Herb & supplement monograph

Huperzine A

Interacts with 219 drugs

Huperzine A is a purified compound from a Chinese clubmoss that acts like a mild cholinesterase inhibitor, similar in mechanism to some prescription Alzheimer's drugs. Some small studies sug...

Read the full Huperzine A monograph → Herb & supplement monograph

Acetyl-l-carnitine

Interacts with 203 drugs

Acetyl-L-carnitine is a form of the amino acid carnitine that the body uses to help produce energy in cells. It is most studied for nerve pain and memory-related conditions, though the evide...

Read the full Acetyl-l-carnitine monograph → Herb & supplement monograph

Phosphatidylserine

Interacts with 219 drugs

Phosphatidylserine is a natural fat-like compound found in cell membranes, especially in the brain, and it is sold mainly to support memory and thinking. Some research suggests possible bene...

Read the full Phosphatidylserine monograph → 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 →
Sources

Sources & How We Checked

Cogni-Flex'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 141 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.

Huperzine A 13 references
  1. Skolnick AA. Old Chinese herbal medicine used for fever yields possible new Alzheimer Disease therapy. JAMA 1997;277:776. DOI
  2. Ye JW, Cai JX, Wang LM, Tang XC. Improving effects of huperzine A on spatial working memory in aged monkeys and young adult monkeys with experimental cognitive impairment. J Pharmacol Exp Ther 1999;288:814-9.. DOI
  3. Wang T, Tang XC. Reversal of scopolamine-induced deficits in radial maze performance by (-)-huperzine A: comparison with E2020 and tacrine. Eur J Pharmacol 1998;349:137-42. PubMed
  4. Xu SS, Gao ZX, Weng Z, et al. Efficacy of tablet huperzine-A on memory, cognition, and behavior in Alzheimer's disease. Zhongguo Yao Li Xue Bao 1995;16:391-5.
  5. Zhang RW, Tang XC, Han YY, et al. [Drug evaluation of huperzine A in the treatment of senile memory disorders]. Chung Kuo Yao Li Hsueh Pao 1991;12:250-2.
  6. Xu SS, Cai ZY, Qu ZW, et al. Huperzine-A in capsules and tablets for treating patients with Alzheimer disease. Zhongguo Yao Li Xue Bao 1999;20:486-90.
  7. Felgenhauer N, Zilker T, Worek F, Eyer P. Intoxication with huperzine A, a potent anticholinesterase found in the fir club moss. J Toxicol Clin Toxicol 2000;38:803-8.. PubMed
  8. Zhang, Z., Wang, X., Chen, Q., Shu, L., Wang, J., and Shan, G. [Clinical efficacy and safety of huperzine Alpha in treatment of mild to moderate Alzheimer disease, a placebo-controlled, double-blind, randomized trial]. Zhonghua Yi Xue Za Zhi 7-25-2002;82
  9. Cheng, D. H., Ren, H., and Tang, X. C. Huperzine A, a novel promising acetylcholinesterase inhibitor. Neuroreport 12-20-1996;8(1):97-101. PubMed
  10. Wang BS, Wang H, Wei ZH, Song YY, Zhang L, Chen HZ. Efficacy and safety of natural acetylcholinesterase inhibitor huperzine A in the treatment of Alzheimer's disease: an updated meta-analysis. J Neural Transm (Vienna) 2009;116(4):457-65. PubMed
  11. Xu ZQ, Liang XM, Juan-Wu, Zhang YF, Zhu CX, Jiang XJ. Treatment with Huperzine A improves cognition in vascular dementia patients. Cell Biochem Biophys 2012;62(1):55-8. PubMed
  12. Yang G, Wang Y, Tian J, Liu JP. Huperzine A for Alzheimer's disease: a systematic review and meta-analysis of randomized clinical trials. PLoS One 2013;8(9):e74916. PubMed
  13. Xing SH, Zhu CX, Zhang R, An L. Huperzine a in the treatment of Alzheimer's disease and vascular dementia: a meta-analysis. Evid Based Complement Alternat Med 2014;2014:363985. PubMed

See these in context on the Huperzine A monograph →

Acetyl-l-carnitine 22 references
  1. Thal LJ, Carta A, Clarke WR, et al. A 1-year multicenter placebo-controlled study of acetyl-L-carnitine in patients with Alzheimer's Disease. Neurology 1996;47:705-11. PubMed
  2. Sano M, Bell K, Cote L, et al. Double-blind parallel design pilot study of acetyl levocarnitine in patients with Alzheimer's Disease. Arch Neurol 1992;49:1137-41. PubMed
  3. Spagnoli A, Lucca U, Menasce G, et al. Long-term acetyl-L-carnitine treatment in Alzheimer's Disease. Neurology 1991;41:1726-32. PubMed
  4. Brooks JO 3rd, Yesavage JA, Carta A, Bravi D. Acetyl L-carnitine slows decline in younger patients with Alzheimer's disease: a reanalysis of a double-blind, placebo-controlled study using the trilinear approach. Int Psychoger 1998;10:193-203. PubMed
  5. Pettegrew JW, Klunk WE, Panchalingam K, et al. Clinical and neurochemical effects of acetyl-L-carnitine in Alzheimer's disease. Neurobiol Aging 1995;16:1-4. PubMed
  6. Rai G, Wright G, Scott L, et al. Double-blind, placebo controlled study of acetyl-l-carnitine in patients with Alzheimer's dementia. Curr Med Res Opin 1990;11:638-47. PubMed
  7. Benvenga S, Ruggeri RM, Russo A, et al. Usefulness of L-carnitine, a naturally occurring peripheral antagonist of thyroid hormone action, in iatrogenic hyperthyroidism: a randomized, double-blind, placebo-controlled clinical trial. J Clin Endocrinol Meta
  8. Montgomery SA, Thal LJ, Amrein R. Meta-analysis of double blind randomized controlled clinical trials of acetyl-L-carnitine versus placebo in the treatment of mild cognitive impairment and mild Alzheimer's disease. Int Clin Psychopharmacol 2003;18:61-71.. PubMed
  9. Martinez E, Domingo P, Roca-Cusachs A. Potentiation of acenocoumarol action by L-carnitine. J Intern Med 1993;233:94.
  10. Hudson S, Tabet N. Acetyl-L-carnitine for dementia. Cochrane Database Syst Rev 2003;2:CD003158.. PubMed
  11. Bachmann HU, Hoffmann A. Interaction of food supplement L-carnitine with oral anticoagulant acenocoumarol. Swiss Med Wkly 2004;134:385. PubMed
  12. De Grandis D, Minardi C. Acetyl-L-carnitine (levacecarnine) in the treatment of diabetic neuropathy. A long-term, randomised, double-blind, placebo-controlled study. Drugs R D 2002;3:223-31. PubMed
  13. 12761 Benvenga S, Amato A, Calvani M, Trimarchi F. Effects of carnitine on thyroid hormone action. Ann N Y Acad Sci 2004;1033:158-67. PubMed
  14. Sima AAF, Calvani M, Mehra M, et al. Acetyl-L-carnitine improves pain, nerve regeneration, and vibratory perception in patients with chronic diabetic neuropathy: An analysis of two randomized, placebo-controlled trials. Diabetes Care 2005;28:89-94.
  15. Youle, M. and Osio, M. A double-blind, parallel-group, placebo-controlled, multicentre study of acetyl L-carnitine in the symptomatic treatment of antiretroviral toxic neuropathy in patients with HIV-1 infection. HIV.Med. 2007;8(4):241-250.
  16. Brennan BP, Jensen JE, Hudson JI, Coit CE, Beaulieu A, Pope HG Jr, Renshaw PF, Cohen BM. A placebo-controlled trial of acetyl-L-carnitine and a-lipoic acid in the treatment of bipolar depression. J Clin Psychopharmacol. 2013 Oct;33(5):627-35.
  17. Ledinek AH, Sajko MC, Rot U. Evaluating the effects of amantadin, modafinil and acetyl-L-carnitine on fatigue in multiple sclerosis--result of a pilot randomized, blind study. Clin Neurol Neurosurg. 2013 Dec;115 Suppl 1:S86-9. PubMed
  18. Martinotti G, Andreoli S, Reina D, Di Nicola M, Ortolani I, Tedeschi D, Fanella F, Pozzi G, Iannoni E, D'Iddio S, Prof LJ. Acetyl-l-Carnitine in the treatment of anhedonia, melancholic and negative symptoms in alcohol dependent subjects. Prog Neuropsychop PubMed
  19. Baek SM, Zheng R, Seo EJ, Hwang DY, Kim BH. Pharmacokinetic comparisons of two acetyl-L-carnitine formulations in healthy Korean volunteers. Int J Clin Pharmacol Ther. 2015;53(11):980-6. PubMed
  20. Goodison G, Overeem K, de Monte V, Siskind D. Mania associated with self-prescribed acetyl-l-carnitine in a man with bipolar I disorder. Australas Psychiatry. 2017;25(1):13-4.
  21. Bruno A, Pandolfo G, Crucitti M, Lorusso S, Zoccali RA, Muscatello MR. Acetyl-L-Carnitine Augmentation of Clozapine in Partial-Responder Schizophrenia: A 12-Week, Open-Label Uncontrolled Preliminary Study. Clin Neuropharmacol. 2016;39(6):277-80. PubMed
  22. Veronese N, Stubbs B, Solmi M, Ajnakina O, Carvalho AF, Maggi S. Acetyl-L-Carnitine Supplementation and the Treatment of Depressive Symptoms: A Systematic Review and Meta-Analysis. Psychosom Med. 2018;80(2):154-9. PubMed

See these in context on the Acetyl-l-carnitine monograph →

Phosphatidylserine 9 references
  1. Crook T, Petrie W, Wells C, Massari DC. Effects of phosphatidylserine in Alzheimer's disease. Psychopharmacol Bull 1992;28:61-6.
  2. Pepping J. Phosphatidylserine. Am J Health-Syst Pharm 1999;56:2038,2043-4.
  3. Kidd PM. Phosphatidylserine; Membrane nutrient for memory. A clinical and mechanistic assessment. Altern Med Rev 1996;1:70-84.
  4. Kim HY, Akbar M, Lau A, et al. Inhibition of neuronal apoptosis by docosahexaenoic acid (22:6n-3). Role of phosphatidylserine in antiapoptotic effect. J Biol Chem 2000;275:35215-23.. PubMed
  5. Zanotti A, Valzelli L, Toffano G. Chronic phosphatidylserine treatment improves spatial memory and passive avoidance in aged rats. Psychopharmacology (Berl) 1989;99:316-21.. PubMed
  6. Schreiber S, Kampf-Sherf O, Gorfine M, et al. An open trial of plant-source derived phosphatydilserine for treatment of age-related cognitive decline. Isr J Psychiatry Relat Sci 2000;37:302-7.
  7. Pepping, J. Phosphatidylserine. Am J Health Syst.Pharm. 10-15-1999;56(20):2038, 2043-2038, 2044.
  8. Monteverde, A., Gnemmi, P., Rossi, F., Monteverde, A., and Finali, G. C. Selegiline in the treatment of mild to moderate Alzheimer-type dementia. Clin.Ther 1990;12(4):315-322.
  9. Vakhapova V, Cohen T, Richter Y, Herzog Y, Kam Y, Korczyn AD. Phosphatidylserine containing omega-3 Fatty acids may improve memory abilities in nondemented elderly individuals with memory complaints: results from an open-label extension study. Dement Geri PubMed

See these in context on the Phosphatidylserine monograph →

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
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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

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