Ginkgo Biloba: What the Big Trials Found, and What It Means for Memopryl

Ginkgo biloba is a tree with fan-shaped leaves, often planted along city streets. Supplements use an extract of the leaf. It is a common herb in memory and thinking supplements.

Why it is in Memopryl

Ginkgo leaf is one of six ingredients named on the brand's "Inside Memopryl" graphic. The bottle front says the formula supports concentration, brain energy and productivity. It makes no claim about memory disease.

What we know about the amount

The ginkgo amount is not published in our files, since the Supplement Facts panel was not part of them. That shapes how the trial results below apply to the capsule.

GEM, short for the Ginkgo Evaluation of Memory study, is the largest ginkgo trial in older adults. It was published in JAMA in 2008 (DeKosky et al., 2008 (GEM)). The design was simple and strict, which is why its result carries weight.

A placebo group matters because memory scores drift over time for many reasons. Comparing two similar groups shows whether the herb itself made a difference.

GEM found that ginkgo did not lower dementia rates. People who took 240 mg a day for about six years developed dementia at similar rates to those on placebo (DeKosky et al., 2008 (GEM)). For a question this large, that is a clear answer.

Why the size of the trial matters

Small studies can show a result by chance. A trial with more than 3,000 people, followed for years, is much harder to fool. That is why reviewers lean on GEM when they discuss ginkgo.

What the result does not say

GEM looked at dementia in adults 75 and over. It did not test focus at work in younger adults, and it did not test blends. Those are separate questions that GEM leaves open.

NCCIH, the federal center for complementary health research, sums up the evidence in two short points. Ginkgo has not been shown to prevent or slow dementia (NCCIH, Ginkgo). More broadly, there is no conclusive evidence that ginkgo prevents or slows cognitive decline (NCCIH, supplements and cognition).

NCCIH also says direct evidence for natural products in this area is lacking. That view matches the National Institute on Aging, which urges caution with supplements that promise better memory (NIA, memory and aging).

Ginkgo may raise bleeding risk when combined with blood thinners such as warfarin (NCCIH, Ginkgo). The concern is extra bruising or bleeding that is hard to stop. It matters most for people who already take drugs that affect clotting.

Before a procedure

Tell your surgeon or dentist about every supplement you take, including ginkgo, before any planned procedure. They may ask you to pause it.

Ginkgo is not the only herb to check

Memopryl also names St. John's wort, which weakens warfarin and many other medicines (NCCIH, St. John's Wort). Our post on St. John's wort and your medicines lists the groups to check.

Setting GEM beside the Memopryl label shows how far apart the two are. The trial tested one herb at a known dose for years. The capsule mixes six ingredients at amounts we cannot see.

Because the amount is missing, no one can say whether a serving is near 240 mg or far below it. The Supplement Facts page explains what is and is not published.

Big trials answer big questions well, but they leave gaps. It helps to be clear about what GEM can and cannot tell a busy adult shopping for focus support.

For the other named ingredients and their studies, see the ingredients page.

Ginkgo has the biggest trial of any Memopryl ingredient, but not the most positive one. The other named ingredients were studied in smaller groups, at doses the label does not let us check.

Bacopa

In 46 healthy adults, 300 mg of bacopa extract a day for 12 weeks improved learning rate and memory consolidation compared with placebo (Stough et al., 2001). The gains showed up only at the 12-week mark.

Phosphatidylserine

In 78 adults aged 50 to 69 with memory complaints, 100 or 300 mg a day for 6 months raised memory scores, mostly in those who started lower (Kato-Kataoka et al., 2010). The FDA allows only a heavily qualified claim for it (FDA, qualified health claims).

Acetyl-L-carnitine

A Cochrane review of 16 trials found no evidence to recommend it for routine use in dementia (Hudson & Tabet, 2003 (Cochrane)). Trials used 1.5 to 3 g a day (NIH ODS, Carnitine).

Ginkgo still appears in ads that hint at protection from memory loss. Those hints do not match the trial evidence. Supplement makers may say a product supports a normal function, but they may not claim it treats or prevents a disease.

The FDA does not approve supplements before they are sold (FDA, Q&A on Dietary Supplements). In 2019 it warned 17 companies selling more than 58 products with illegal Alzheimer's claims (FDA, Alzheimer's claims, 2019). If an ad for any ginkgo product promises to stop dementia, walk away.

What to look for instead

Plain support claims with an asterisk, a readable Supplement Facts panel and clear medicine warnings. Our focus supplement checklist scores these points one by one.

If you are thinking about a product with ginkgo, a few steps keep the decision grounded in facts.