Ginkgo biloba, adverse effects

A metaanalysis indicated that EGb 761 (an extract of ginkgo biloba) may have some therapeutic effect at doses of 120 to 240 mg of the standard leaf extract twice daily. Because of limited efficacy data, the potential for adverse effects (e.g., nausea, vomiting, diarrhea, headache, dizziness, weakness, and hemorrhage), and the poor standardization of herbal products, it is recommended that ginkgo biloba be used only with caution. 

Adverse effects listed in the German Commission E Ginkgo biloba leaf extract monograph include gastrointestinal upset, headache, and rash (Blumenthal, 1998). 

Most herbs do not have life-threatening adverse effects. Ginkgo biloba should be taken with caution when taking antiplatelets or anticoagulants because it will increase the risk of bleeding. 

Ginkgo biloba has been associated with platelet, bleeding and clotting disorders and there are isolated reports of serious adverse reactions after its concurrent use with antiplatelet drugs such as aspirin, clopidogrel and ticlopidine. An animal study su ests that Kangen-Katyu may also enhance the antiplatelet and antithrombotic effects of ticlopidine. 

Woerdenbag, H., and T. Van Beek. 1997. Ginkgo biloba. In Adverse effects cf herbal drugs. Volume 3, edited by De Smet, P. A.G.M., K. KeUer, R. Hansel, and R.F. Ghandler. New York Springer. 

Placebo-controlled studies An adequately powered placebo-controlled trial of the effect of Ginkgo biloba in the primary prevention of dementia included over 3000 volunteers aged 75 years and over [67 ]. They were randomized to twice daily doses of either Ginkgo biloba extract 120 mg or placebo and were followed for a median of 6.1 years. The extract had no effect on the incidence of dementia. The adverse... 

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