Ginkgo biloba L. · herb
Evidence tier: insufficient
Improves blood flow to the brain and extremities. Supports memory, concentration, and circulation in older adults.
Acts mainly on the circulation and the brain. The flavones and terpene lactones are thought to widen blood vessels, reduce blood viscosity and cut platelet stickiness, with antioxidant activity in cells. Partly demonstrated rather than merely proposed, and note that the same platelet effect is why EMA writes a bleeding precaution, a stop 3 to 4 days before surgery, and a pregnancy contraindication. A demonstrated mechanism is not a demonstrated clinical benefit.
Insufficient, and the flagship claim was DISPROVED. The GEM trial (Ginkgo Evaluation of Memory, PMID 19017911, JAMA) randomised 3069 people aged 75 or older to 120 mg of ginkgo twice daily or placebo for a median of six years and found ginkgo 'was not effective in reducing either the overall incidence rate of dementia or AD incidence'. The hazard ratio for all cause dementia was 1.12, meaning the ginkgo arm numerically had slightly MORE dementia, not less. This is the largest, longest, best powered ginkgo trial ever run and it found nothing. For treating existing dementia, the Cochrane review of 36 trials calls the evidence 'inconsistent and unreliable' (PMID 19160216). For tinnitus, the Cochrane review found ginkgo 'may have little to no effect' at low to very low certainty (PMID 36383762). NCCIH, verbatim: 'There's no conclusive evidence that ginkgo is helpful for any health condition.' EMA does register a well established use of the refined standardised extract for age associated cognitive impairment and mild dementia, but that is a regulatory status for one specific extract and it says nothing about prevention.
120 to 240 mg of the refined standardised leaf extract as a single dose, 240 mg daily, for at least 8 weeks (the EMA well established use dose). Traditional use of powdered leaf is 750 mg daily. Never eat raw or roasted ginkgo seeds, which are toxic and separate from the leaf extract.
120 to 240 mg standardised extract (EGb 761) daily, split morning and midday. 6 to 8 weeks for full effect.
Significant anticoagulant interaction. Avoid with warfarin, aspirin, NSAIDs, and 2 weeks before surgery.
Pregnancy: avoid
Breastfeeding: avoid
Active compounds: flavonoid glycosides (flavones), terpene lactones, ginkgolide A, ginkgolide B, ginkgolide C, bilobalide
Remedies using Ginkgo Biloba · Browse by body system · Check it against what you take
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.