Ginkgo biloba benefits, side effects and how to take it
What ginkgo biloba is, what the trials show for memory, dementia and tinnitus, the forms on sale, how to take it and who should avoid it.
- Written by
- Alex W.
- Last updated
- Reading time
- 8 min read
Overview
Ginkgo biloba is a leaf extract from an ancient tree. Trials found no memory benefit in healthy adults and little or none in mild memory problems, with possible small benefits in dementia on weak evidence. The usual amount is 240 mg of extract a day. Avoid it in pregnancy and check first if you take blood thinners.
Key points
- Ginkgo supplements use an extract of the leaf, standardised to set levels of two groups of compounds.
- Reviews found no effect on memory in healthy adults and little or none in people with mild memory problems.
- A 6-year trial in over 3,000 older adults found it didn't prevent dementia.
- The European herbal monograph gives 240 mg of extract a day for at least 8 weeks.
- Ask your GP or pharmacist first if you take blood thinners or have surgery coming up, and avoid it in pregnancy.
What is ginkgo biloba?
The ginkgo tree is so old that it's often called a living fossil. It's the last surviving species of an ancient family of plants, and it has a long history in Chinese medicine [1]. Today it's better known as one of the best-selling herbal supplements, and the part in the tablets is the fan-shaped leaf.
Most ginkgo supplements hold a leaf extract rather than the dried leaf itself. The extract used in the research is made from dried leaves and then refined and standardised, so each batch carries a set level of two groups of compounds. The European standard for this refined extract is 22% to 27% flavone glycosides and 5% to 7% terpene lactones, with no more than 5 parts per million of ginkgolic acids, which can irritate the skin and are kept low on purpose [2].
People take ginkgo hoping it will help memory and circulation. It sits on many lists of nootropics, the supplements people take for their thinking, but the research is less encouraging than the shelf space suggests.
What is ginkgo good for?
Ginkgo has been tested in many trials, and a US health agency sums them up bluntly: it hasn't been shown to work for any condition it has been studied for [1]. The picture changes a little depending on who took it.
| Who took it | Best evidence | What it found |
|---|---|---|
| Healthy adults | Review of 13 memory trials, 1,132 people | No measurable effect on memory, attention or planning [3] |
| Mild memory problems | 12 trials, 1,913 people | Probably little or no effect at six months [4] |
| People with dementia | 13 trials, 3,288 people | May give small to moderate benefits at six months, low certainty [4] |
| Older adults, to prevent dementia | Trial of 3,069 people for about 6 years | No fewer cases of dementia than on a placebo [5] |
| Tinnitus | 12 trials, 1,915 people | May have little or no effect, very uncertain [6] |
| Leg pain when walking | 14 trials, 739 people | No clinically meaningful benefit [7] |
The largest single trial is the most telling. In the US, 3,069 people aged 75 or over took 120 mg of a standardised extract twice a day or a placebo for a median of 6.1 years. Dementia developed in 277 people on ginkgo and 246 on the placebo, a difference that could easily be down to chance [5].
The one hopeful line is for people who already have dementia, where a 2026 Cochrane review found possible small benefits. It rated that evidence as low certainty, and more than half of the 82 studies it found were run in China Early [4]. So for healthy adults hoping for a sharper memory, the tally is short. There's no good evidence it helps. Our Atlas page lists the ginkgo studies one by one, with what each found.
Ginkgo tablets, capsules, tea and seeds
Extract tablets and capsules. These are the form the trials used. Look for a label that gives the amount of extract and its flavone glycosides and terpene lactones, because those figures show it matches the standardised extract the research tested [2].
Leaf powder and tea. The European herbal monograph lists powdered leaf only as a traditional remedy for heavy legs and cold hands and feet, based on long use rather than trials [8]. A tea or a capsule of plain leaf gives no set amount of the compounds the trials measured.
Seeds. Ginkgo nuts are eaten in some cuisines, but fresh seeds are toxic and roasted ones have caused serious side effects [1]. A compound in the seeds can cause seizures [2]. They're a different thing from a leaf supplement.
Quality varies more than you might expect. When researchers tested 59 ginkgo supplements, 48 contained something that shouldn't have been there, such as added rutin or quercetin, or extracts of sophora or buckwheat, plants rich in the same compounds [9]. The percentages on the label only help if what's inside matches them, so a brand that publishes independent test results tells you more.
How to take ginkgo
Ginkgo extract is licensed as a herbal medicine in parts of Europe, so its official monograph gives the clearest guide to an amount. For the refined extract, it gives 240 mg a day, taken as one dose or split into two, for at least 8 weeks. If nothing has improved after 3 months, it advises checking with a doctor [8]. The large US trial gave 120 mg twice a day, the same total [5].
Take it with or without food, at the same time each day. Supplements vary in strength, so follow the amount on your own label and don't take more than it says.
Side effects and who should avoid ginkgo
For most adults, leaf extract is likely to be safe in moderate amounts, and it has been taken in studies lasting up to 6 years [1]. The most common side effects are headache, dizziness and stomach upset [1]. In the Cochrane review, side effects were no more common on ginkgo than on a placebo [4].
Bleeding is the side effect people worry about most. A review of 18 trials found standardised extract didn't change blood clotting tests [10], but bleeding has been reported in people taking it, and the risk matters most for anyone already on medicines that thin the blood [1][8].
So ginkgo is an old tree with a modest scientific record. If you're curious about it for your memory, the research says to keep your expectations low, and our guide to what causes brain fog covers the everyday things that make more difference.
Frequently asked questions
What is ginkgo biloba good for?
It hasn't been shown to help any health condition in good trials. Reviews found no effect on memory in healthy adults and little or none in people with mild memory problems, though people with dementia may get small benefits on low-certainty evidence [3][4].
What are the side effects of ginkgo biloba?
The most common are headache, dizziness and stomach upset. Bleeding has also been reported, so take care if you take blood-thinning medicines or have surgery coming up [1][8].
Does ginkgo biloba help memory?
Not in healthy adults. A review of 13 trials found no measurable effect on memory, and a 6-year trial in people over 75 found it didn't prevent dementia [3][5].
Can you take ginkgo with blood thinners?
Ask your GP or pharmacist first. Ginkgo may raise the risk of bleeding with warfarin, aspirin and other medicines that affect clotting, and the European monograph advises care with all of them [1][8].
Does ginkgo help tinnitus?
Probably not. A 2022 Cochrane review of 12 trials found it may have little or no effect on tinnitus, and the evidence was very uncertain [6].
How long does ginkgo take to work?
The European monograph says to take it for at least 8 weeks, and to see a doctor if nothing has improved after 3 months. The trials in the Cochrane review measured results at six months [4][8].
Can you eat ginkgo nuts?
Take care. Fresh ginkgo seeds are toxic, and serious side effects have followed eating roasted ones, so they aren't a substitute for a leaf supplement [1].
Read more in our guide to L-theanine, another supplement people take for focus.
References
Every study here is listed so you can read it yourself. This guide is for general information and doesn't replace advice from your GP or pharmacist. We check it again at least every six months.
- National Center for Complementary and Integrative Health. Ginkgo. Last updated February 2025. Accessed 25 October 2026. nccih.nih.gov/health/ginkgo
- European Medicines Agency, Committee on Herbal Medicinal Products (2014). Assessment report on Ginkgo biloba L., folium. EMA/HMPC/321095/2012. Accessed 25 October 2026. ema.europa.eu
- Laws KR, Sweetnam H, Kondel TK (2012). Is Ginkgo biloba a cognitive enhancer in healthy individuals? A meta-analysis. Human Psychopharmacology 27(6): 527–533. PMID 23001963
- Wieland LS, Ludeman E, Chi Y, et al. (2026). Ginkgo biloba for cognitive impairment and dementia. Cochrane Database of Systematic Reviews 2: CD013661. PMID 41641880
- DeKosky ST, Williamson JD, Fitzpatrick AL, et al. (2008). Ginkgo biloba for prevention of dementia: a randomized controlled trial. JAMA 300(19): 2253–2262. PMID 19017911
- Sereda M, Xia J, Scutt P, et al. (2022). Ginkgo biloba for tinnitus. Cochrane Database of Systematic Reviews 11: CD013514. PMID 36383762
- Nicolaï SP, Kruidenier LM, Bendermacher BL, et al. (2013). Ginkgo biloba for intermittent claudication. Cochrane Database of Systematic Reviews 6: CD006888. PMID 23744597
- European Medicines Agency, Committee on Herbal Medicinal Products (2015). European Union herbal monograph on Ginkgo biloba L., folium. EMA/HMPC/321097/2012. Accessed 25 October 2026. ema.europa.eu
- Frommenwiler DA, Booker A, Vila R, et al. (2019). Comprehensive HPTLC fingerprinting as a tool for a simplified analysis of purity of ginkgo products. Journal of Ethnopharmacology 243: 112084. PMID 31306695
- Kellermann AJ, Kloft C (2011). Is there a risk of bleeding associated with standardized Ginkgo biloba extract therapy? A systematic review and meta-analysis. Pharmacotherapy 31(5): 490–502. PMID 21923430
