What Is Ginkgo Biloba Good For? Trials, UK Registration, Cautions

Ginkgo leaf extract has been tested in large trials for memory and dementia: in the largest, 3,069 adults aged 75 and over took 120 mg twice a day or placebo for about six years, and dementia developed in 277 on ginkgo and 246 on placebo. One UK ginkgo product is a registered traditional herbal medicine for Raynaud's syndrome and tinnitus, "based on traditional use only".^{1, 2} No authorised health claim exists for ginkgo in Great Britain; this page reports the trials as counts and the cautions as the NHS states them. This page is part of our guide to whether mushroom supplements work.

What is ginkgo biloba, and which part is in supplements?

Ginkgo biloba is the maidenhair tree, planted along British streets for its fan-shaped leaves, yellow each October. Supplements and the one registered UK medicine use a dried leaf extract: 100 mg per registered tablet, 120 mg twice a day in the large trials.^{1, 2} The Great Britain nutrition and health claims register has no row for ginkgo, so a label may name the plant and nothing it does.

Is ginkgo good for memory or dementia? What the trials found

Two large trials in people without dementia were null; a 2026 Cochrane review finds probably no effect in mild cognitive impairment and a small-to-moderate, low-certainty benefit in people who already have dementia; in healthy adults the pooled effect sizes are close to zero.^{1, 3, 4, 5}

GEM: 3,069 US adults aged 75 and over took 120 mg of extract twice a day or placebo for a median 6.1 years; dementia developed in 277 on ginkgo and 246 on placebo, not a significant difference.¹ GuidAge: 2,854 French adults with memory complaints took the same dose for five years; 61 on ginkgo and 73 on placebo developed Alzheimer's disease, not significant; deaths, strokes and bleeding events did not differ.³ The 2026 Cochrane review of 82 trials and 10,613 people with cognitive impairment or dementia: in mild cognitive impairment "ginkgo probably has little or no effect at six months" (moderate certainty); in dementia "there may be small to moderate benefits at six months for global status, cognition, and ADLs", low certainty because the trials disagreed widely.⁴ In healthy adults, a meta-analysis of 13 memory trials in 1,132 people found effect sizes "non-significant and close to zero".⁵

What does the UK traditional herbal registration for ginkgo mean?

The MHRA list dated 27 October 2025 holds one ginkgo registration, THR 20243/0002, listed as a traditional herbal medicinal product "used to relieve the symptoms of Raynaud's syndrome and tinnitus", "based on traditional use only".² The MHRA's guidance sets the test: a registration is "only granted if the medicine is used for minor health conditions" that need no medical supervision.² The registration records long use for two minor symptoms, not proof of effect; neither indication is memory, and a food supplement containing ginkgo is not a registered medicine and cannot carry the wording. The NHS adds that herbal medicines "are not tested in the same way as standard medicines".⁶

Is ginkgo good for circulation, tinnitus or Raynaud's?

The registration rests on traditional use; the trials are null for tinnitus and leg circulation and conflicting for Raynaud's. Tinnitus: the 2022 Cochrane review of 12 trials and 1,915 people found a mean difference of -1.35 points on a 100-point handicap scale, "very uncertain".⁷ Intermittent claudication, leg pain from narrowed arteries: 14 trials in 739 people added 64.5 metres of treadmill distance, not significant and, the reviewers judged, inflated by publication bias.⁸ Raynaud's: three small trials disagree; the two most recent found attacks down 33% against 31% on placebo in 41 people at 120 mg twice a day for ten weeks, and, in 93 Korean patients, the blood-pressure medicine nifedipine improved attack rates by 50.1% against 31.0% on ginkgo.^{9, 10}

Does ginkgo thin the blood, and can you take it with warfarin or before surgery?

In 18 trials of 1,985 people, standardised ginkgo extract did not change platelet clumping or clotting times; isolated bleeding cases have been reported, so people on anticoagulants tell their clinic.¹¹ With warfarin, a 2017 systematic review of randomised studies found that ginkgo "did not significantly alter" warfarin's clotting effect, with conflicting results on blood levels; a 2013 review found no clinically relevant interaction at up to 240 mg a day of one standardised extract, adding that "a relevant potential for drug interactions cannot be excluded for poorly standardized" extracts "used in many food supplements".¹² The NHS warfarin page (reviewed 24 February 2026) says to "tell your doctor if you're taking any other medicines, herbal remedies, vitamins or supplements".¹³ So do aspirin and clopidogrel. Before an operation, tell the pre-operative assessment team about every supplement; no source names a stopping interval. The NHS bleeding-caution list is on who should not take turmeric; the medicine-by-medicine table covers mushroom capsules that add ginkgo.

Are ginkgo nuts or seeds safe?

Not in quantity, and never for children. The seeds contain 4'-O-methylpyridoxine, a vitamin B6 antagonist: a two-year-old convulsed nine hours after eating a large number, and reported poisoning cases "usually involve children who exhibit repetitive seizures that can be fatal".¹⁴ Supplements and the registered medicine are leaf extracts; this caution is about the seeds.

Who should not take ginkgo, and what side effects are reported?

The NHS herbal medicines page (reviewed 1 May 2026) says not to take herbal medicines if "you're pregnant or breastfeeding" or "you have kidney or liver problems", lists statins, antidepressants, diabetes and blood-pressure medicines, "blood thinning medicine, such as warfarin" and the combined pill as medicines that "do not mix well", states "Herbal medicines are not recommended for children", and says to "Always check first with a pharmacist".⁶ Epilepsy: two people with controlled epilepsy had seizures within two weeks of starting ginkgo extract, and one fatal seizure occurred with low phenytoin and valproate levels, an interaction proposed rather than proved; in four trials of 1,154 people seizures were no more common than on placebo; anyone with epilepsy or on an anticonvulsant asks their specialist first.^{7, 15} Antidepressants: no safety trial exists, and the NHS lists them above.⁶ Side effects in trials: gastrointestinal upset, headache and allergic reaction, no more common than on placebo across four trials of 1,175 people; in the dementia trials adverse events matched placebo, while in one three-month study of people with cognitive complaints they "may" have been more common.^{4, 7} A suspected reaction goes to the MHRA Yellow Card scheme.¹⁶

Frequently asked questions

Can you take lion's mane and ginkgo together?

One mouse study tested a ginkgo-plus-lion's-mane mixture in a scopolamine memory model; no human trial exists.¹⁷ Lion's mane's cautions are on what lion's mane is good for, and the wider combinations question on ashwagandha vs lion's mane.

Can you take ginkgo and ginseng together?

Four studies of one fixed combination (60 mg ginkgo extract with 100 mg Panax ginseng extract per capsule), from one research group: a 14-week trial in 256 healthy middle-aged volunteers reported a 7.5% improvement in a computerised memory index; the other three were single-dose studies in young adults; none measured safety beyond tolerability.¹⁸ Both plants' cautions apply; ginseng's are on what ginseng is good for.

How much ginkgo did the trials use?

120 mg of standardised leaf extract twice a day in GEM, GuidAge and the null Raynaud's trial; 240 mg a day is the maximum recommended dose of the standardised extract in the interaction review; 100 mg per tablet in the registered medicine.^{1, 2, 3, 9, 12} None is a recommendation.

Is ginkgo a nootropic?

"Nootropic" is a search word, not a claim any UK supplement may make, because no authorised health claim exists for ginkgo; in healthy adults the trials measured no change, with effect sizes close to zero across 13 trials.⁵

Sources

1. DeKosky ST. Ginkgo biloba for prevention of dementia: a randomized controlled trial. JAMA, 2008. PubMed 19017911.
2. MHRA. Herbal medicines granted a traditional herbal registration (THR), list dated 27 October 2025. gov.uk. Apply for a traditional herbal registration. gov.uk.
3. Vellas B. Long-term use of standardised Ginkgo biloba extract for the prevention of Alzheimer's disease (GuidAge). Lancet Neurology, 2012. PubMed 22959217.
4. Wieland LS. Ginkgo biloba for cognitive impairment and dementia. Cochrane Database Syst Rev, 2026. PubMed 41641880.
5. Laws KR. Is Ginkgo biloba a cognitive enhancer in healthy individuals? A meta-analysis. Human Psychopharmacology, 2012. PubMed 23001963.
6. NHS. Herbal medicines and complementary therapies. Reviewed 1 May 2026. nhs.uk.
7. Sereda M. Ginkgo biloba for tinnitus. Cochrane Database Syst Rev, 2022. PubMed 36383762.
8. Nicolaï SP. Ginkgo biloba for intermittent claudication. Cochrane Database Syst Rev, 2013. PubMed 23744597.
9. Bredie SJ. Journal of Cardiovascular Pharmacology, 2012. PubMed 22030896.
10. Choi WS. Clinical Rheumatology, 2009. PubMed 19159999.
11. Kellermann AJ. Is there a risk of bleeding associated with standardized Ginkgo biloba extract therapy? Pharmacotherapy, 2011. PubMed 21923430.
12. Choi S. Pharmacokinetic and pharmacodynamic interactions of herbal medicine with warfarin. PLoS One, 2017. PubMed 28797065. Unger M. Pharmacokinetic drug interactions involving Ginkgo biloba. Drug Metabolism Reviews, 2013. PubMed 23865865.
13. NHS. Warfarin. Reviewed 24 February 2026. nhs.uk.
14. Kajiyama Y. Ginkgo seed poisoning. Pediatrics, 2002. PubMed 11826216.
15. Granger AS. Ginkgo biloba precipitating epileptic seizures. Age and Ageing, 2001. PubMed 11742783. Kupiec T. Fatal seizures due to potential herb-drug interactions with Ginkgo biloba. Journal of Analytical Toxicology, 2005. PubMed 16419414.
16. MHRA. Yellow Card. yellowcard.mhra.gov.uk.
17. Hong SM. A mixture of Ginkgo biloba leaf and Hericium erinaceus fruit extract attenuates scopolamine-induced memory impairments in mice. Oxidative Medicine and Cellular Longevity, 2022. PubMed 35126824.
18. Wesnes KA. The memory enhancing effects of a Ginkgo biloba/Panax ginseng combination in healthy middle-aged volunteers. Psychopharmacology, 2000. PubMed 11140327.

This article is general information, not medical advice. Ginkgo supplements are foods, not medicines; anyone on a regular medicine, with epilepsy, pregnant or breastfeeding, or due an operation asks a pharmacist or GP first, and never stops a prescribed medicine for a supplement.