Our pick · Ginkgo Biloba

NOW Supplements Ginkgo Biloba 120mg

Check priceBuy now →

Ginkgo Biloba

One of the most-studied herbal supplements in history, with mixed but meaningful evidence for circulation and cognition — though the large dementia-prevention trials were negative.

By editorialUpdated 2026-05-251 min read

What it's actually good for

Ginkgo biloba is one of the oldest and most extensively studied herbal supplements in the world, with hundreds of clinical trials and several large-scale investigations. The evidence picture is genuinely mixed, which is why honest assessment matters here. On the positive side: standardized ginkgo extract (EGb 761, 120-240 mg/day) has shown modest improvements in cognitive processing speed, memory, and attention in smaller RCTs and meta-analyses, particularly in older adults already experiencing cognitive decline. It also has documented vasodilatory and antiplatelet effects that translate to modest improvements in peripheral circulation (intermittent claudication). On the negative side: the largest and most rigorous trial — the GEM study with over 3,000 participants — found that ginkgo did not prevent dementia or slow cognitive decline in healthy older adults over a median of 6 years. This is a critical result that tempers the enthusiasm from smaller studies. Ginkgo earns a B because the overall evidence base is large and the biological activity is real (improved blood flow, antioxidant effects), but the failure of the definitive prevention trial means we cannot claim it protects cognitive function in healthy people. It may be more appropriate for symptomatic management in populations with existing vascular or cognitive complaints than as a preventive nootropic.

Claim-by-claim

Each claim graded independently

The overall grade is the floor. Some claims are stronger or weaker than the headline.

B

Improves cognitive function

Smaller RCTs and meta-analyses show modest improvements in cognitive speed, memory, and attention, particularly in older adults with existing cognitive decline. However, the large GEM trial (n=3069) found no benefit for preventing dementia in healthy older adults.

B

Supports peripheral and cerebral blood circulation

Ginkgo's flavonoid glycosides and terpene lactones have documented vasodilatory and antiplatelet effects. Clinical trials show improvements in symptoms of peripheral arterial disease (intermittent claudication), though effect sizes are modest.

Sources

3 cited
[01]METAGinkgo biloba for cognitive impairment and dementiaBirks J, Grimley Evans J. Cochrane Database Syst Rev. 2009
[02]RCTGinkgo biloba for prevention of dementia: a randomized controlled trial (GEM Study)DeKosky ST, Williamson JD, Fitzpatrick AL, et al.. JAMA. 2008
[03]GOVTGinkgoNational Center for Complementary and Integrative Health (NCCIH). 2020

When the evidence changes, we’ll tell you.

One short email a month. New A-grades, downgraded claims, and reader questions.

Medical disclaimer. The information on this site is provided for educational purposes only and is not intended as medical advice. It does not constitute a diagnosis, treatment plan, or recommendation for any specific health condition. Always consult a qualified healthcare professional before making changes to your supplement regimen, diet, or lifestyle — especially if you are pregnant, nursing, taking medications, or managing a medical condition.

Affiliate disclosure. Some links on this site are affiliate links. If you purchase through them, we may earn a small commission at no extra cost to you. This never influences our editorial assessments — products are graded solely on the evidence.