Supplement analysis backed by scientific evidence · PT · ES · DE · FR

← All supplements
Limited evidenceBrain & cognition

Ginkgo Biloba

The largest and longest trial ever run on ginkgo found it did nothing: over a median 6.1 years in 3,069 older adults, EGb 761 did not slow cognitive decline at all. The dementia-treatment literature is inconsistent and dominated by small older trials. This is a popular supplement with genuinely poor evidence.

View on iHerb Ships to 180+ countries · welcome discount for new customers

What the science says

  • Does not prevent cognitive decline in older adults Strong evidence

    The Ginkgo Evaluation of Memory (GEM) study randomized 3,069 adults aged 72-96 to 120 mg EGb 761 twice daily or placebo for a median 6.1 years. Annual rates of decline were essentially identical for memory, attention, visuospatial ability, language and executive function, with no difference on the 3MSE (p = 0.71) or ADAS-Cog (p = 0.97), and no benefit in any subgroup including mild cognitive impairment or APOE*E4 carriers. This is a large, well-powered, unambiguously negative trial.

  • Treating dementia and cognitive impairment Limited evidence

    A Cochrane review of 36 trials found most were small and under three months long. Of the four most recent trials to report, three found no difference from placebo and one reported very large effects. The reviewers concluded that evidence of predictable, clinically significant benefit is inconsistent and unreliable, and that publication bias cannot be excluded.

  • Tinnitus, claudication and other uses Limited evidence

    Ginkgo is widely promoted for tinnitus, intermittent claudication and vertigo. Trials in these areas are mostly small, older and inconsistent, and where larger trials exist the effect sizes shrink toward nothing, following the same pattern as the cognition literature.

Dosage & safety

Studied doseTrials used EGb 761 standardized to 24% flavone glycosides and 6% terpene lactones at 120-240 mg/day in divided doses. The GEM prevention trial used 120 mg twice daily for over 6 years, which is the dose and duration that failed. Cheaper non-standardized leaf powders were not what was tested.
SafetyGinkgo is well tolerated in trials, with no excess adverse events versus placebo in the Cochrane review, but it has antiplatelet activity and case reports link it to intracranial, ocular and post-surgical bleeding, particularly alongside aspirin, NSAIDs, warfarin or DOACs. Stop at least 1-2 weeks before surgery. It modulates several CYP enzymes (notably CYP2C19) and can lower levels of drugs such as efavirenz and some anticonvulsants; seizures have been reported and it is generally avoided in epilepsy. Raw or roasted ginkgo seeds contain ginkgotoxin (4'-O-methylpyridoxine) and can cause seizures and death, especially in children; never eat them. In Germany and several other countries standardized ginkgo extract is a registered medicine rather than a food supplement.

How to take it

TimingTiming does not matter; split the dose across the day as the trials did.
With food?Food makes no meaningful difference.
Worth knowingOnly EGb 761-type extract standardised to 24% flavone glycosides and 6% terpene lactones has been tested; cheap leaf powder is a different product.

Interactions

With medications

  • warfarin, DOACs, aspirin, clopidogrel and NSAIDs

    Ginkgo has antiplatelet activity and case reports link the combinations to intracranial, ocular and post-surgical bleeding. do not combine without medical supervision, and stop 1-2 weeks before surgery

  • anticonvulsants and any drug that lowers seizure threshold

    Ginkgo lowers levels of some anticonvulsants and seizures have been reported on it. avoid it if you have epilepsy

  • efavirenz and other CYP2C19 substrates

    Ginkgo induces CYP2C19 and can drop drug levels below the effective range. do not combine without checking with your pharmacist

With other supplements

  • fish oil, garlic, vitamin E and other antiplatelet supplements

    Additive bleeding risk. do not stack them, especially around surgery

Well-established interactions only — this is not a complete list. Always tell your doctor and pharmacist what you take.

Frequently asked questions

Does ginkgo biloba improve memory or prevent dementia?

No: the GEM trial gave 3,069 older adults 120 mg of ginkgo extract twice daily for a median 6.1 years and found no slowing of cognitive decline in any domain or subgroup. This is strong negative evidence from a large, well-powered trial.

Does ginkgo help tinnitus?

The evidence is limited: ginkgo trials for tinnitus, claudication and vertigo are mostly small, older and inconsistent. Where larger trials exist, the effect sizes shrink toward nothing.

Is ginkgo safe with blood thinners?

Ginkgo has antiplatelet activity, and case reports link it to brain, eye and post-surgical bleeding, especially with aspirin, NSAIDs, warfarin or DOACs. Do not combine them without medical supervision, and stop ginkgo 1-2 weeks before surgery.

What are the risks of ginkgo biloba?

Ginkgo extract is well tolerated in trials but can increase bleeding, lower levels of drugs such as efavirenz and some anticonvulsants, and is generally avoided in epilepsy. Never eat raw or roasted ginkgo seeds, which contain ginkgotoxin and can cause seizures and death, especially in children.

Scientific references

Where to buy

Natrol, Ginkgo Biloba, 60 Capsules

View on iHerb

Ships to 180+ countries · welcome discount for new customers

Referral link — this site may earn a commission on purchases.

Related in Brain & cognition