Ginkgo Biloba: How It Works, Evidence & Safety

Last updated: June 2026 · Reviewed by the FactoWiki Editorial Team

Ginkgo biloba is a herbal extract studied for circulation and cognitive support. It appears in brain-support formulas, and the evidence for memory benefits is mixed.

What is Ginkgo Biloba?

Ginkgo is one of the oldest tree species, and its leaf extract is a long-used herbal supplement, most often standardised for flavonoids and terpenes.

How Ginkgo Biloba works

Ginkgo is thought to support blood flow and act as an antioxidant, which is the rationale behind its use for circulation and cognition.

What the evidence says

• The NIH's complementary-health agency summarises ginkgo research, noting it has not been shown to prevent cognitive decline. (NIH NCCIH)
• Trials on ginkgo and memory have produced mixed results overall. (PubMed research)

How much do studies use?

Standardised extracts have been studied around 120-240 mg per day. This is research information, not a recommendation.

Safety and side effects

Generally well tolerated; headache or stomach upset can occur. Ginkgo may thin the blood.

Who should avoid Ginkgo Biloba?

People on blood thinners or who are about to have surgery should avoid ginkgo or consult a doctor, due to bleeding risk.

Frequently asked questions

Does ginkgo improve memory?

Evidence is mixed; large trials have not shown it prevents cognitive decline. Any benefit is likely modest and gradual.

Is ginkgo safe with blood thinners?

Caution is advised, as ginkgo may increase bleeding risk. Check with a doctor first.