Ginkgo biloba

What it is

Ginkgo biloba is one of the oldest living tree species. Extracts from its fan-shaped leaves are among the best-known herbal supplements for memory and concentration.

Large trials in older adults have mostly not shown that ginkgo prevents memory decline or dementia. It remains popular anyway.

How it works

Ginkgo contains flavonoids and terpenes that may improve blood flow, act as antioxidants and affect platelet activity, which is relevant to bleeding risk. Brain effects in healthy people are small if any.

What the evidence says

• Weak Preventing dementia or memory decline
  Large, well-run trials have not shown a benefit.
• Limited Memory in people with existing dementia
  Some trials show small benefits with specific standardised extracts, but results are inconsistent.
• Weak Memory and focus in healthy adults
  Little reliable evidence of benefit.
• Limited Leg pain from poor circulation (claudication)
  Small increases in walking distance in some trials; not a substitute for medical care.
• Weak Tinnitus
  Not shown to help reliably.

Evidence ratings are our plain-English summary of how much good human research exists, not a promise of results. How we rate evidence.

Dosage and timing

• Trials typically use 120-240 mg a day of a standardised extract.
• Doses are split, often twice daily.
• Stop before planned surgery as advised by your clinician, due to the bleeding risk.
• Trials run for weeks to months; long-term safety data is limited.

Forms and what to look for

• Standardised extracts such as EGb 761 (24% flavonoid glycosides, 6% terpene lactones) are the best-studied.
• Raw leaf or tea is not recommended because it can contain ginkgolic acids, which are allergenic and potentially toxic.
• Check the label for the percentage standardisation.
• Combination brain blends rarely list how much ginkgo they contain.

What to expect, and when

• Studies run 6-24 weeks.
• Any benefit would be subtle and slow.
• If you notice no difference after about 3 months, there is little reason to continue.

Side effects

• Headache, dizziness and stomach upset.
• Skin reactions or allergy.
• Increased bleeding or bruising.
• Palpitations, in some people.

Interactions

• Warfarin, aspirin, clopidogrel, other anticoagulants and antiplatelets: increased bleeding risk.
• NSAIDs such as ibuprofen: possible additive bleeding risk.
• Other supplements affecting clotting, such as fish oil, garlic and vitamin E at high doses.
• Anti-seizure medicines: ginkgo may lower the seizure threshold.
• Some antidepressants and medicines processed by liver enzymes; ask a pharmacist.

Who should avoid it

• Anyone on blood thinners or with a bleeding disorder.
• People with epilepsy or a history of seizures.
• Anyone with surgery or dental extractions planned in the next 2 weeks.
• Pregnancy and breastfeeding, particularly close to labour.
• People allergic to ginkgo products or related plants (such as mango or cashew relatives for ginkgolic acid sensitivity).

Risks and safety

• Bleeding events, including rare reports of serious bleeds, particularly with blood thinners.
• Seizure risk in vulnerable people.
• Poor-quality products can contain little ginkgo or too much ginkgolic acid.

Buying well: quality and testing

• Choose a standardised extract with a stated percentage of flavonoids and terpene lactones.
• Third-party testing seals (USP, NSF) help.
• Avoid brain-boosting blends that hide the ginkgo dose.
• Avoid raw leaf preparations.

Bottom line

Ginkgo has not lived up to its reputation for memory, and its effect on bleeding is the part that matters. If you take blood thinners, have a bleeding disorder or epilepsy, or have surgery coming up, leave it alone. For everyone else, it is a low-yield supplement; sleep, exercise and social contact are much better evidence-backed investments in your brain.