Does ginkgo increase blood flow to the brain?

Modest increases have been measured with standardised extract. Whether that matters clinically is a separate question.

Will it improve my memory?

Large trials found no meaningful cognitive benefit and no reduction in dementia incidence.

120-240 mg daily of a standardised extract such as EGb 761, split into two doses.

Is it safe with blood thinners?

No. Combining them raises bleeding risk, including rare intracranial haemorrhage.

Do I need to stop before surgery?

Yes, at least two weeks beforehand.

Outcome

Moderate Evidence

Effectiveness 3/5

Ginkgo Biloba for Cerebral Blood Flow

Ginkgo reliably increases measured cerebral perfusion; cognitive benefits are smaller and mostly seen in impaired populations.

Overview

Ginkgo biloba is one of the oldest and most heavily marketed brain supplements, and cerebral blood flow is the mechanism nearly always cited for it. Both parts of that claim deserve separating.

There is reasonable evidence that standardised ginkgo extract modestly increases cerebral perfusion, measurable by transcranial Doppler and imaging in some studies. That is a physiological effect with plausible mechanisms behind it. What has not followed is clinical benefit. Large, well-conducted trials designed to test whether ginkgo prevents dementia or improves cognition in older adults have been essentially negative. The blood flow effect is real; the cognitive payoff people buy it for has not materialised.

No studies are currently linked to this pairing

This page reflects established pharmacology and conventional dosing rather than trial data attached to this outcome in our library.

How It Works

Standardised extracts such as EGb 761 contain roughly 24 percent flavone glycosides and 6 percent terpene lactones. The terpene fraction includes ginkgolides, which antagonise platelet-activating factor, reducing platelet aggregation and improving blood rheology.

Ginkgo has also been reported to promote endothelial nitric oxide availability and produce mild vasodilation, and to reduce red cell aggregation, all of which would improve microcirculatory flow in small cerebral vessels. The flavonoid fraction contributes antioxidant activity and has shown neuroprotective effects against ischaemic and oxidative injury in animal models. The gap between these mechanisms and clinical outcomes is the central problem: perfusion in a healthy or mildly impaired brain may simply not be the limiting factor for cognition.

Dosing & Protocol

Dosing is well standardised because most research used a single extract specification.

Context	Dose	Form	Timing
Standard studied dose	120-240 mg daily	EGb 761 standardised extract	Split into 2 doses with food
Common starting dose	120 mg daily	Standardised extract (24% flavone glycosides, 6% terpene lactones)	With a meal
Upper studied range	240 mg daily	Standardised extract	Divided doses
Assessment window	8-12 weeks	-	Effects, where present, build slowly

Standardisation matters

Unstandardised ginkgo leaf products vary enormously and may contain ginkgolic acids, which are removed from pharmaceutical-grade extracts because of allergenicity.

Evidence

There are currently no studies linked to this pairing in our library, so no study list is shown.

Across the wider literature, imaging and Doppler studies have reported modest increases in cerebral blood flow with standardised ginkgo extract, and its platelet-activating factor antagonism and rheological effects are well characterised pharmacologically. The clinical picture is far less favourable. Large multi-year randomised trials in older adults found no reduction in dementia incidence and no meaningful cognitive benefit. Cochrane reviews of ginkgo for cognitive impairment have described the evidence as inconsistent and unreliable. There is somewhat better signal for intermittent claudication and tinnitus than for cognition, and blood flow itself remains a surrogate endpoint.

Perfusion changed, cognition did not

Increased cerebral blood flow has not translated into demonstrated cognitive or dementia-prevention benefit in large trials.

Safety

Ginkgo is usually well tolerated, with headache, dizziness, gastrointestinal upset and occasional allergic skin reactions the common complaints.

Bleeding is the real risk

Case reports describe spontaneous bleeding including intracranial haemorrhage, particularly alongside anticoagulants or antiplatelets. Stop ginkgo at least two weeks before surgery.

Ginkgo seeds are toxic and must never be substituted for leaf extract. Rodent studies at very high doses raised carcinogenicity questions of uncertain human relevance. People with epilepsy should be cautious, as ginkgo has been associated with reduced seizure threshold, and it should be avoided in pregnancy.

Interactions & Conflicts

Ginkgo has one of the more clinically significant interaction profiles among common herbal supplements.

Interacts with	Severity	Mechanism	Action
Warfarin, DOACs, aspirin and clopidogrel	high	Platelet-activating factor antagonism adds to bleeding risk	Avoid unless specifically cleared by your doctor
Surgery or dental procedures	high	Increased bleeding risk	Stop at least 2 weeks beforehand
Anticonvulsants	moderate	Possible reduced seizure threshold and altered drug levels	Avoid in epilepsy without neurology advice
SSRIs and MAOIs	moderate	Case reports of serotonergic effects	Discuss with your prescriber

References

No studies are currently linked to this pairing, so no reference list is available. This section will populate as evidence is added to the library.

Frequently Asked Questions

Medical Disclaimer

The information provided on this website is for educational and informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or before starting any supplement regimen.

Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.