Reminder: this information is not a substitute for medical advice! Consult a healthcare professional about whether these treatments are appropriate.
Ginkgo biloba, or ginkgo, is an extract made from the leaves of the ginkgo tree. Trials of ginkgo to improve memory and thinking have had mixed results. As for prevention, a large 8 year study did not show the supplement to be effective for reducing the risk of dementia.
There have been case reports of ginkgo causing bleeding, and at least in theory, the supplement may be dangerous when combined with other blood-thinning medications or supplements, including aspirin and coumadin.