Ginkgo biloba is one of the oldest living species of tree. Extracts from its leaves (referred to here as “ginkgo”) are used in and as dietary supplements associated with a variety of health claims. Unfortunately, the most common claims are for treating problems such as cognitive decline, memory loss, mood disturbances (for example, depression and anxiety), and difficulties with focus and concentration. By definition, dietary supplements are not intended to treat “problems.” Regardless, ginkgo is one of the most popular dietary supplement ingredients on the market today. You might see it labeled on brain health products as “Ginkgo biloba extract (GBE),” “Egb761,” or “GK 501.”

There isn’t enough solid research to confirm whether ginkgo can help optimize performance and boost brain health.

Does ginkgo work to boost brain health and performance?

Several studies have investigated whether ginkgo as a dietary supplement can boost brain health and enhance cognitive performance in healthy adults (ages 18–60 years) who don’t have any signs of cognitive impairment. Some of the latest research has shown enhanced performance on some tasks related to attention, memory, and problem solving, in as little as one hour—and up to 6 hours—after taking one capsule of 120–360 mg ginkgo. However, the evidence is inconsistent in terms of the specific tasks tested as well as the serving sizes used in research. As a result, it’s hard to say if and how much benefit you might gain. Some other research has actually shown a decline in performance of certain tasks immediately after taking 120 mg ginkgo.

Only a few studies have examined the use of ginkgo longer than once a day for up to 12 weeks. The latest research has shown that taking 120 mg ginkgo per day for 12 weeks does not seem to result in better cognitive performance than a placebo.

Is ginkgo safe as a dietary supplement?

Ginkgo appears to be safe for most people when taken as a dietary supplement in amounts of 120–360 mg per day for up to 12 weeks and possibly longer. Possible minor side effects include headache and nausea. Some case reports of unexplained bleeding, moodiness, and irregular heartbeat exist. Ginkgo might be unsafe for people prone to bleeding or for pregnant women close to term due to the possibility of excess bleeding. It also might not be safe to take with certain medications.  If you’re considering ginkgo, always consult a physician first, and look for a dietary supplement product with evidence of third-party certification or verification, as there have been reports of ginkgo products adulterated with contaminants.

There is no reliable evidence that taking more than 360 mg per day of ginkgo is safe. In addition, ginkgo should never to be taken by mouth in the raw form, as it can be poisonous.

Can ginkgo produce a positive result on a military drug screening test?

As a dietary supplement, ginkgo is not prohibited for use by Military Service Members and should not produce a positive result on a routine military drug screening test.

The bottom line about ginkgo

The evidence presented here is for the single ingredient Ginkgo biloba extract and does not represent the evidence for ginkgo when combined with other ingredients. With multiple-ingredient supplements, it is nearly impossible to know which substance might cause any effect, either benefit or harm. In addition, the evidence presented is only for people with no signs of cognitive decline. And remember: Always look for a seal as evidence of third-party certification or verification, and talk with a healthcare provider before you use ginkgo.


Updated 15 January 2021


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