Drug Database - Ginko

Common Names: ginkgo, Ginkgo biloba, fossil tree, maidenhair tree, Japanese silver apricot, baiguo, bai guo ye, kew tree, yinhsing (yin-hsing)

Latin Name: Ginkgo biloba

Classification: Herb

Ginkgo leaf extract has been used to treat a variety of ailments and conditions, including asthma, bronchitis, fatigue, and tinnitus (ringing or roaring sounds in the ears). Today, people use ginkgo leaf extracts hoping to improve memory; to treat or help prevent Alzheimer's disease and other types of dementia; to decrease intermittent claudication (leg pain caused by narrowing arteries); and to treat sexual dysfunction, multiple sclerosis, tinnitus, and other health conditions.

Ginkgo inhibits the action of platelets in the blood, thus interfering with blood coagulation. Don't use ginkgo if you are taking the blood thinner warfarin (Coumadin) or antiplatelet drugs such as clopidogrel (Plavix®). Ginkgo may lower blood sugar, so don't use it if you are already taking drugs for diabetes.

Numerous studies of ginkgo have been done for a variety of conditions. Some promising results have been seen for intermittent claudication, but larger, well-designed research studies are needed.

An NCCAM-funded study of the well-characterized ginkgo product, EGb-761, found it ineffective in lowering the overall incidence of dementia and Alzheimer's disease in the elderly. In this clinical trial, known as the Ginkgo Evaluation of Memory study, researchers recruited more than 3,000 volunteers age 75 and over who took 240 mg of ginkgo daily. Participants were followed for an average of approximately 6 years.

Some smaller studies for memory enhancement have had promising results, but 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.

Other NCCAM-funded research includes studies on ginkgo for asthma, symptoms of multiple sclerosis, vascular function (intermittent claudication), cognitive decline, sexual dysfunction due to antidepressants, and insulin resistance. NCCAM is also looking at potential interactions between ginkgo and prescription drugs.

Side effects of ginkgo may include headache, nausea, gastrointestinal upset, diarrhea, dizziness, or allergic skin reactions. More severe allergic reactions have occasionally been reported.

There are some data to suggest that ginkgo can increase bleeding risk, so people who take anticoagulant drugs, have bleeding disorders, or have scheduled surgery or dental procedures should use caution and talk to a health care provider if using ginkgo.

Uncooked ginkgo seeds contain a chemical known as ginkgotoxin, which can cause seizures. Consuming large quantities of seeds over time can cause death. Ginkgo leaf and ginkgo leaf extracts appear to contain little ginkgotoxin.

Tell your health care providers about any complementary and alternative practices you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.