Ginkgo biloba, commonly known as ginkgo or gingko, is a tree species native to China, but has been cultivated worldwide for several hundred years. The Gingko is the last living species of the order Ginkgoales, which originated over 290 million years ago. Therefore, it is also called a "living fossil".
Extracts for medicinal use are produced from the leaves of the ginkgo tree. These extracts are said to have a positive effect on brain performance and memory. It is also used to relieve dizziness and ringing in the ears. However, there is no scientific evidence to support these effects. Systematic reviews have shown that there is also no scientific evidence of efficacy in the treatment of hypertension, menopause-related cognitive decline, tinnitus, or altitude sickness. However, there is weak evidence that ginkgo affects dementia and tardive dyskinesia symptoms in people with schizophrenia.