Does it work?

More studies are still needed. Ginkgo seems to improve blood circulation, which might help the brain, eyes, ears, and legs function better, but we do not recommend it for the treatment of dementia based on the current evidence.

The results of some clinical trials have suggested that ginkgo can improve the symptoms of dementia. Unfortunately, most of these trials were small or poorly designed. A trial sponsored by the National Institute on Aging of more than 200 healthy adults over age 60 found that ginkgo taken for 6 weeks did not improve memory. (Dodge HH, Zitzelberger T, Oken BS, et al. A randomized placebo-controlled trial of ginkgo biloba for the prevention of cognitive decline. Neurology. 2008;70:1809-17.)

NCCAM is conducting:

• A clinical trial of ginkgo with more than 3,000 volunteers to see if the herb prevents the onset of dementia and, specifically, Alzheimer's disease; slows cognitive decline and functional disability (for example, inability to prepare meals); reduces the incidence of cardiovascular disease; and decreases the rate of premature death.
• Studies using ginkgo for asthma, symptoms of multiple sclerosis, blood vessel function (intermittent claudication), cognitive decline, sexual dysfunction due to antidepressants, and insulin resistance.
• Investigations of potential interactions between ginkgo and prescription drugs.