Ginkgo

© Steven Foster

This fact sheet provides basic information about ginkgo—common names, 

what the science says, potential side effects and cautions, and resources for 

more information.

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

The ginkgo tree is one of the oldest types of trees in the world. Ginkgo 

seeds have been used in traditional Chinese medicine for thousands of 

years, and cooked seeds are occasionally eaten. Historically, 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, folk uses of ginkgo leaf extracts include 

attempts 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.

Extracts are usually taken from the ginkgo leaf and are used to make tablets, 

capsules, or teas. Occasionally, ginkgo extracts are used in skin products.

What the Science Says 

• Numerous studies of ginkgo have been done for a variety of 

conditions. Among the most widely researched are dementia, 

memory impairment, intermittent claudication, and tinnitus.

• 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. Further analysis of 

the same data also found ginkgo to be ineffective in slowing 

cognitive decline, lowering blood pressure, or reducing the 

incidence of hypertension. 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 of ginkgo 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.
• Overall, the evidence on ginkgo for symptoms of intermittent claudication has not yet shown a significant 

benefit for this condition, although several small studies have found modest improvements. There is 

conflicting evidence on the efficacy of ginkgo for tinnitus.

• Other NCCAM-funded research includes studies of ginkgo for symptoms of multiple sclerosis, 

intermittent claudication, cognitive decline, sexual dysfunction due to antidepressants, insulin 

resistance, and short-term memory loss associated with electroconvulsive therapy for depression.

Side Effects and Cautions 

• 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.

• Fresh (raw) ginkgo seeds contain large amounts of a chemical called ginkgotoxin, which can cause serious adverse 

reactions—even seizures and death. Roasted seeds can also be dangerous. Products made from standardized 

ginkgo leaf extracts contain little ginkgotoxin and appear to be safe when used orally and appropriately.

• Tell all your health care providers about any complementary health practices you use. Give them a full 

picture of what you do to manage your health. This will help ensure coordinated and safe care. For tips 

about talking with your health care providers about complementary and alternative medicine, see 

NCCAM’s Time to Talk campaign at nccam.nih.gov/timetotalk/. 

Sources

Brinkley TE, Lovato JF, Arnold AM, et al. Effect of Ginkgo biloba on blood pressure and incidence of hypertension in elderly men and 

women. American Journal of Hypertension. 2010;23(5):528-533.

DeKosky ST, Williamson JD, Fitzpatrick AL, et al. Ginkgo biloba for prevention of dementia: a randomized controlled trial. Journal of the 

American Medical Association. 2008;300(19):2253-2262.

Ginkgo. Natural Medicines Comprehensive Database Web site. Accessed at www.naturaldatabase.com on August 20, 2009.

Ginkgo (Ginkgo biloba L.). Natural Standard Database Web site. Accessed at www.naturalstandard.com on August 20, 2009.

Ginkgo biloba leaf extract. In: Blumenthal M, Goldberg A, Brinckman J, eds. Herbal Medicine: Expanded Commission E Monographs. Newton, 

MA: Lippincott Williams & Wilkins; 2000:359-366.

Snitz BE, O'Meara ES, Carlson MC, et al. Ginkgo biloba for preventing cognitive decline in older adults: a randomized trial. Journal of the 

American Medical Association. 2009;302(24):2663-2670.

Solomon PR, Adams F, Silver A, et al. Ginkgo for memory enhancement: a randomized controlled trial. Journal of the American Medical 

Association. 2002;288(7):835-840.

Strømgaard K, Vogensen SB, Nakanishi K. Ginkgo biloba. In: Coates P, Blackman M, Cragg G, et al., eds. Encyclopedia of Dietary Supplements.

New York, NY: Marcel Dekker; 2005:249-257.

For More Information

Visit the NCCAM Web site at nccam.nih.gov and view Using Dietary Supplements Wisely (nccam.nih.gov/health/supplements/wiseuse.htm).

NCCAM Clearinghouse

Toll-free in the U.S.: 1-888-644-6226

TTY (for deaf and hard-of-hearing callers): 1-866-464-3615

E-mail: info@nccam.nih.gov

PubMed®

Web site: www.ncbi.nlm.nih.gov/sites/entrez

NIH Office of Dietary Supplements

Web site: www.ods.od.nih.gov

NIH National Library of Medicine’s MedlinePlus

Ginkgo Listing: www.nlm.nih.gov/medlineplus/druginfo/natural/333.html

This publication is not copyrighted and is in the public domain. Duplication is encouraged.

NCCAM has provided this material for your information. It is not intended to substitute for the medical expertise and advice of your 

primary health care provider. We encourage you to discuss any decisions about treatment or care with your health care provider. The 

mention of any product, service, or therapy is not an endorsement by NCCAM.

National Institutes of Health

♦♦♦

U.S. Department of Health and Human Services

D290

Created September 2005

Updated April 2012