Ginkgo: what the research says and how to choose a supplement

Ginkgo (Ginkgo biloba) is one of the oldest trees in the world. Its leaf extract is often chosen in the hope of better memory and concentration.

In this article you will learn what the research actually shows, how to recognise a quality extract on the label and when it is better not to take ginkgo.

What is ginkgo extract?

Supplements use ginkgo leaf extract. It contains two groups of substances: flavonoid glycosides and terpene lactones.⁴

The most commonly studied extract is standardised: it contains about 24% flavonoid glycosides and about 6% terpene lactones.⁴ On the label this is shown as “24/6” or “24% / 6%”.

Example. If a capsule contains 120 mg of “24/6” extract, it contains about 28.8 mg of flavonoid glycosides and 7.2 mg of terpene lactones. If the label only says “ginkgo leaf powder”, it is not a standardised extract.

Ginkgo leaves naturally contain ginkgolic acids, which can cause allergies. In a quality extract, their amount is reduced to a minimum.⁴

What does the research show?

Dementia prevention. The study included 3,069 people over 75 years of age. For about 6 years they took 120 mg of extract twice a day or a placebo. The number of dementia cases was similar in both groups.²

Memory and thinking. The results in research reviews are mixed. Some studies found a small benefit, others none.⁵ Therefore, ginkgo is not a way to protect yourself from memory problems.

In some EU countries, standardised ginkgo extract is registered as a herbal medicinal product. In that case, it is prescribed and its use is monitored by a doctor.⁴ Food supplements are not intended to treat diseases.

If you notice that your memory is getting worse, first see a doctor. Forgetfulness can also be caused by other factors, such as vitamin B12 deficiency or poor sleep.⁶

When is it better not to take ginkgo?

• You take blood-thinning medicines or aspirin – the risk of bleeding may increase.³
• You have surgery or a dental procedure coming up – stop taking ginkgo a few days beforehand. Discuss the exact timing with your doctor.⁴
• You are pregnant or breastfeeding.⁴
• You have epilepsy – talk to your doctor first.⁴

The most common side effects are headache, digestive disorders and allergic skin reactions.³ Do not eat raw ginkgo seeds or make tea from unprocessed leaves – they can be poisonous.³

How to choose a ginkgo supplement?

• Look for the “24/6” mark. This way you will know it is a standardised extract.
• Check the amount of extract. Studies most often used 120–240 mg of extract per day, divided into 1–2 doses.⁴
• Ginkgolic acids. Give preference to products whose label states a low amount of them.
• Do not combine several products. Ginkgo is often found in “memory” blends. Check the composition of all the products you take.

Selected ginkgo products

Commercial information. The products listed here are available in our shop. This is not a ranking of effectiveness. Before buying, check the composition and instructions for use on the product page.

Frequently asked questions

How long does it take to feel an effect?

In studies, the extract was most often taken for at least 8 weeks.⁴ However, the effect differs from person to person, and many people do not notice any.

Can ginkgo be taken together with omega-3 or vitamin E?

Large amounts of omega-3 can also affect blood clotting. If you take several such supplements or medicines, talk to your doctor or pharmacist.³

Is ginkgo suitable for students before exams?

There is not enough evidence that ginkgo improves memory in healthy young people.⁵ Getting enough sleep and taking regular breaks while studying is a simpler first step.

Scientific sources

1. Europos Komisija. EU Register of nutrition and health claims made on foods. ec.europa.eu
2. DeKosky ST, Williamson JD, Fitzpatrick AL et al. Ginkgo biloba for prevention of dementia: a randomized controlled trial. JAMA. 2008;300(19):2253–2262. doi:10.1001/jama.2008.683
3. NIH National Center for Complementary and Integrative Health. Ginkgo. nccih.nih.gov
4. European Medicines Agency, HMPC. European Union herbal monograph on Ginkgo biloba L., folium. EMA/HMPC/321097/2012. ema.europa.eu
5. Birks J, Grimley Evans J. Ginkgo biloba for cognitive impairment and dementia. Cochrane Database Syst Rev. 2009;(1):CD003120. doi:10.1002/14651858.CD003120.pub3
6. NIH Office of Dietary Supplements. Vitamin B12 – Fact Sheet for Health Professionals. ods.od.nih.gov
7. Life Extension. Ginkgo Biloba Certified Extract, 120 mg, 365 capsules. Product label.
8. Doctor's Best. Extra Strength Ginkgo, 120 mg, 120 capsules. Product label.
9. Holland & Barrett. Ginkgo Biloba, 60 mg, 120 tablets. Product label.
10. NOW Foods. Ginkgo Biloba, 60 mg, 120 capsules. Product label.