Myths About Ginkgo Biloba
Ginkgo biloba is one of the world’s best-selling herbal products and is often described as a "memory herb". Its reputation was built on decades of traditional use and early European research, but large modern trials have changed the picture considerably. Our editorial team examines the most common beliefs about ginkgo.
Where ginkgo’s reputation comes from
The ginkgo tree is one of the oldest living plant species, and its leaves have been used in traditional Chinese practice for centuries. Modern interest began in Germany, where a standardised leaf extract known as EGb 761 was developed and studied for circulation and cognitive complaints.
Standardised ginkgo extracts typically contain around 24% flavone glycosides and 6% terpene lactones, including ginkgolides and bilobalide. These compounds have antioxidant properties and influence blood flow and platelet function in laboratory studies.
Early trials in older people with cognitive impairment reported modest benefits, and ginkgo became popular as a natural brain tonic. Over time, larger and better-designed trials tested whether it could prevent decline in healthy people or improve memory in young adults.
The answer from those trials is the main reason so many popular beliefs about ginkgo now count as myths.
Myth 1: ginkgo prevents dementia
The Ginkgo Evaluation of Memory (GEM) study, led by DeKosky and published in 2008, followed more than 3,000 older adults taking 120 mg of extract twice daily or placebo for a median of about six years. Ginkgo did not reduce the incidence of dementia or Alzheimer’s disease.
A follow-up analysis by Snitz and colleagues from the same trial found no slowing of cognitive decline in memory, attention or executive function. The French GuidAge study, reported by Vellas and colleagues in 2012, similarly found no significant reduction in progression to Alzheimer’s disease over five years.
These are some of the largest and longest prevention trials ever conducted for a dietary supplement, and their results were consistently negative. Taking ginkgo to ward off dementia is therefore not supported by evidence.
Some clinicians still discuss specific ginkgo extracts for symptomatic treatment in diagnosed dementia, where several smaller studies and meta-analyses report modest effects. This is a separate medical question that requires specialist advice.
Myth 2: ginkgo sharpens memory in healthy people
Many students and professionals take ginkgo hoping to improve concentration and recall. A randomised trial by Solomon and colleagues in healthy adults over 60 found no improvement in memory, learning, attention or concentration after six weeks compared with placebo.
Studies in younger adults have generally been small and inconsistent. Occasional positive findings on specific tests have not been reliably replicated, and the overall evidence does not support ginkgo as a cognitive enhancer.
The belief that ginkgo benefits sports performance through better circulation has even less support. There is no robust evidence that it improves endurance, strength or recovery in athletes.
Altitude sickness is another area where ginkgo has been tested. Results were conflicting, and prescribed medicines remain the evidence-based option for prevention.
Myth 3: herbal means harmless
Ginkgo affects platelet function, which raises the question of bleeding. Case reports have described bleeding events, including brain haemorrhage, in people taking ginkgo, and a systematic review by Bent and colleagues summarised these reports, while noting that cause and effect could not be established.
A meta-analysis by Kellermann and Kloft of randomised trials found no significant increase in bleeding risk with standardised extract compared with placebo. However, the trials often excluded people at higher risk, such as those on anticoagulants.
| Situation | Concern | Advice |
|---|---|---|
| Warfarin, DOACs, antiplatelet drugs | Possible additive bleeding effect | Avoid unless approved by doctor |
| Planned surgery or dental extraction | Bleeding during procedure | Stop in advance, as advised by clinician |
| Epilepsy | Ginkgotoxin in seeds; rare seizure reports | Seek medical advice |
| Pregnancy and breastfeeding | Insufficient safety data | Not recommended |
Ginkgo seeds and raw leaves are not the same as standardised extract. Seeds contain a compound linked to seizures, and unprocessed leaves contain ginkgolic acids that can cause allergic reactions.
Myth 4: all ginkgo products are equivalent
Most trials used specific standardised extracts. Products on the market vary widely in quality, and investigations in various countries have found adulteration with cheaper flavonoids added to mimic the expected chemical fingerprint.
- Look for a defined extract with stated flavone glycoside and terpene lactone content.
- In the UK, a Traditional Herbal Registration (THR) mark indicates quality controls by the MHRA.
- Avoid products with vague "ginkgo leaf powder" labelling.
- Tell your GP, pharmacist or dentist that you take ginkgo.
Common mild side effects include headache, dizziness and stomach upset. Allergic skin reactions are possible.
Ginkgo is not prohibited in sport, but as with any herbal product, contamination remains a theoretical risk for tested athletes.
The editorial team's conclusions
Ginkgo biloba does not prevent dementia and does not reliably improve memory in healthy people, according to large, long-term trials.
It is not a sports supplement, and its benefits for circulation in healthy athletes are unproven.
The main practical issue is safety: bleeding interactions with anticoagulant and antiplatelet drugs, surgery and variable product quality.
You may also be interested in our articles on nootropics in sport, the evidence behind adaptogens, and how to read herbal supplement labels.
References
- DeKosky ST, Williamson JD, Fitzpatrick AL, Kronmal RA, Ives DG, Saxton JA, et al. Ginkgo biloba for prevention of dementia: a randomized controlled trial. JAMA. 2008;300(19):2253–2262.
- Snitz BE, O’Meara ES, Carlson MC, Arnold AM, Ives DG, Rapp SR, et al. Ginkgo biloba for preventing cognitive decline in older adults: a randomized trial. JAMA. 2009;302(24):2663–2670.
- Vellas B, Coley N, Ousset PJ, Berrut G, Dartigues JF, Dubois B, et al. Long-term use of standardised ginkgo biloba extract for the prevention of Alzheimer’s disease (GuidAge): a randomised placebo-controlled trial. Lancet Neurol. 2012;11(10):851–859.
- Solomon PR, Adams F, Silver A, Zimmer J, DeVeaux R. Ginkgo for memory enhancement: a randomized controlled trial. JAMA. 2002;288(7):835–840.
- 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(7):657–661.
- 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(5):490–502.
