Ginkgo biloba
Summary
Ginkgo leaf extract did not lower dementia risk or slow cognitive decline in large trials of 2,854–3,069 older adults (no-effect). In people who already had dementia, the EGb 761 extract at 240 mg/day improved cognition and function scores over 22–26 weeks (grade B). NCCIH notes possible bleeding risk with anticoagulants.
Key facts
- A standardised extract of ginkgo leaves; fresh or roasted seeds are toxic[1]
- No reduction in dementia or cognitive decline in the 3,069-person GEM and 2,854-person GuidAge trials[2][3]
- EGb 761 at 240 mg/day stabilised or slowed decline over 22–26 weeks (9 trials, 2,561 patients)[5]
- Generally well tolerated; possible bleeding risk with anticoagulants and may be unsafe in pregnancy (NCCIH)[1]
- 5 graded human outcomes on this page
- October 11, 2026
How it works
ProposedGinkgo flavonoids and terpene lactones (ginkgolides, bilobalide) are proposed to improve blood flow and protect neurons; ginkgolide B inhibits platelet-activating factor.[6][1]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| Cognition | Grade B | Improved | Meta-analysis of 9 trials · n = 2,561 · 2015 | 2 rows |
| Safety | Grade C | No effect | Meta-analysis of 18 trials · n = 1,985 · 2011 | 1 row |
| Dementia risk | No effect | No effect | RCT · n = 3,069 · 2008 | 2 rows |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Cognition and function in existing dementia | Improved | Grade B | Meta-analysis · n = 2,561 · 2015 People with cognitive impairment or dementia in 9 trials Form: Ginkgo extract EGb 761 · Dose: Mainly 240 mg/day · Duration: 22–26 weeks EGb 761 at 240 mg/day stabilised or slowed decline in cognition, function and behaviour versus placebo. | 25114079 (opens PubMed)Source [5] |
| Blood clotting measures | No effect | Grade C | Meta-analysis · n = 1,985 · 2011 Adults in 18 RCTs (87% with dementia, artery disease or diabetes) Form: Standardised ginkgo extract · Dose: Varied across trials · Duration: Varied across trials Hemostasis measures did not indicate a higher bleeding risk versus placebo. | 21923430 (opens PubMed)Source [6] |
| Incident dementia in older adults | No effect | No effect | RCT · n = 3,069 · 2008 Adults aged 75+ with normal cognition or MCI Form: Ginkgo extract EGb 761 · Dose: 120 mg twice daily · Duration: Median about 6 years Dementia and Alzheimer incidence did not differ from placebo. | 19017911 (opens PubMed)Source [2] |
| Rate of cognitive decline | No effect | No effect | RCT · n = 3,069 · 2009 Adults aged 72–96 in the GEM study Form: Ginkgo extract EGb 761 · Dose: 120 mg twice daily · Duration: Median 6.1 years Annual decline in memory, attention and other domains did not differ from placebo. | 20040554 (opens PubMed)Source [4] |
| Progression to Alzheimer disease | No effect | No effect | RCT · n = 2,854 · 2012 Adults aged 70+ with memory complaints Form: Ginkgo extract EGb 761 · Dose: 120 mg twice daily · Duration: 5 years Long-term use did not reduce progression to Alzheimer disease versus placebo. | 22959217 (opens PubMed)Source [3] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| Standardised leaf extract (EGb 761 type: 24% flavone glycosides, 6% terpene lactones) | Varies | The extract used in the large trials; no head-to-head absorption data versus non-standardised products. | Common side effects are dizziness, stomach upset and headache.[1] | All major dementia trials |
| Ginkgo seeds (food use) | Varies | Not a supplement form in the trials cited here. | Fresh seeds are toxic, and roasted seeds have caused serious side effects.[1] | Not studied as a supplement |
Studied doses
Doses studied in human trials ranged from 120 mg/day to 240 mg/day of standardised extract, given as 120 mg twice daily for about 6 years in prevention trials and 240 mg/day for 22–26 weeks in dementia trials.[2][5]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
Who should be careful
- Pregnancy
- NCCIH says ginkgo may be unsafe in pregnancy and might cause early labour or extra bleeding near delivery.[1]
- Blood thinners or surgery
- Possible added bleeding risk with anticoagulants.[1]
- Ginkgo seeds
- Fresh seeds are toxic; roasted seeds and the crude plant have caused serious side effects.[1]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
Where to buy Ginkgo biloba
Products from brands we partner with that contain Ginkgo biloba. Listing a product is not a claim that it works; check the amount per serving against the doses studied above, and the label for other ingredients.
- SupersmartPaid linkGinkgo Biloba3 capsules: 180 mg leaf extract standardised to 24% flavone glycosides and 6% terpene lactones (the standardisation used in the large trials); 30 servingsShop at Supersmart (opens in new tab)Price and label checked 2026-10-11 on the brand’s site.
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Frequently asked questions
Does ginkgo improve memory in healthy people?
Large trials in older adults found no slowing of cognitive decline over about 6 years.[4]
Does ginkgo lower dementia risk?
No. The GEM and GuidAge trials found no reduction in dementia or Alzheimer disease.[2][3]
Is ginkgo useful once dementia is diagnosed?
Pooled trials of EGb 761 at 240 mg/day found slower decline over about 6 months.[5]
Sources
- [1]Ginkgo (Last Updated: February 2025). National Center for Complementary and Integrative Health (NCCIH), 2025. fact-sheet
- [2]Ginkgo biloba for prevention of dementia: a randomized controlled trial.. JAMA, 2008. RCT
- [3]Long-term use of standardised Ginkgo biloba extract for the prevention of Alzheimer's disease (GuidAge): a randomised placebo-controlled trial.. Lancet Neurol, 2012. RCT
- [4]Ginkgo biloba for preventing cognitive decline in older adults: a randomized trial.. JAMA, 2009. RCT
- [5]Efficacy and adverse effects of ginkgo biloba for cognitive impairment and dementia: a systematic review and meta-analysis.. J Alzheimers Dis, 2015. meta-analysis
- [6]Is there a risk of bleeding associated with standardized Ginkgo biloba extract therapy? A systematic review and meta-analysis.. Pharmacotherapy, 2011. meta-analysis
What changed
- First draft. Every PMID checked against NCBI E-utilities (title, journal and year taken from the PubMed record) and each evidence row written from its PubMed abstract.