Topic Overview

What is ginkgo biloba?

Ginkgo extract, from the leaves of the Ginkgo biloba tree, has been used for thousands of years in traditional Chinese medicine. It also is the most commonly used herbal medicine in Europe. Although the benefits of ginkgo are not entirely understood, it is known that ginkgo has properties that may help treat certain conditions. Ginkgo may:

• Improve blood flow in the brain and elsewhere in the body.
• Reduce inflammation.
• Act as an antioxidant (like vitamin E) to fight cell damage.
• Improve memory in people with memory impairment.

In the United States, ginkgo is considered a dietary supplement.

What is ginkgo used for?

People have used ginkgo to treat a variety of health conditions. There is some evidence that ginkgo may be helpful in the treatment of:

• Blood flow disorders (circulatory disorders), such as thrombophlebitis, Raynaud's phenomenon, and peripheral arterial disease.
• Asthma and allergies.
• Mental decline (dementia).
• Memory and concentration problems, anxiety, stress, and mood problems.

Many people take ginkgo hoping to improve and preserve memory. But some studies show that there is no convincing evidence that it can help improve memory and prevent dementia.^{3, 1, 2}

Ginkgo is widely used throughout Europe to treat age-related dementia, including Alzheimer's disease.

Is ginkgo safe?

Ginkgo appears to be safe and has few side effects. Direct contact with the pulp of the ginkgo tree may cause a skin reaction similar to poison ivy, but this is not a problem with ginkgo that is taken by mouth (oral supplements). Experts don't know whether ginkgo is safe for women who are pregnant or breast-feeding, so these women should consult a doctor before taking ginkgo.

Bleeding problems are the only major complication that has been linked to use of ginkgo, and the risk seems to be very low. Ginkgo is not recommended for people who are taking medicines that thin the blood (anticoagulants), such as warfarin (Coumadin), aspirin, or NSAIDs. This is because ginkgo may reduce the blood's ability to clot. The combined effect of ginkgo and these medicines may be harmful.

The U.S. Food and Drug Administration (FDA) does not regulate dietary supplements in the same way it regulates medicines. A dietary supplement can be sold with limited or no research on how well it works or on its safety.

Always tell your doctor if you are using a dietary supplement or if you are thinking about combining a dietary supplement with your conventional medical treatment. It may not be safe to forgo your conventional medical treatment and rely only on a dietary supplement. This is especially important for women who are pregnant or breast-feeding.

When using dietary supplements, keep in mind the following:

• Like conventional medicines, dietary supplements may cause side effects, trigger allergic reactions, or interact with prescription and nonprescription medicines or other supplements you might be taking. A side effect or interaction with another medicine or supplement may make other health conditions worse.
• The way dietary supplements are manufactured may not be standardized. Because of this, how well they work or any side effects they cause may differ among brands or even within different lots of the same brand. The form of supplement that you buy in health food or grocery stores may not be the same as the form used in research.
• Other than for vitamins and minerals, the long-term effects of most dietary supplements are not known.