Ginkgo biloba (ginkgo) is a tree whose leaves are often used as a dietary supplement for the purposes of cognitive improvement. These leaves contain a variety of potentially bioactive compounds, including several types of flavonoids and terpenoids.
Ginkgo biloba seems to improve aspects of cognitive function in people with dementia. There is also preliminary evidence that ginkgo can improve cognitive function in healthy middle-aged people and healthy older people. It is unclear whether ginkgo can improve cognitive function in healthy younger people, as most studies on this population have reported no clear benefit.
No significant safety concerns associated with Ginkgo biloba leaf extract have been clearly identified in human clinical trials. Although case studies have indicated that ginkgo might increase bleeding risk, a meta-analysis of 18 randomized controlled trials found no higher risk of bleeding in participants who took standardized extracts. There have been rare reports of seizures among people with epilepsy who supplemented with ginkgo, perhaps due to stimulation of the enzymatic breakdown of anticonvulsant medication. Finally, experiments in rodents have suggested that ginkgo extract may be carcinogenic.
For cognitive enhancement, take 120-240mg, one to four hours before performance. To alleviate cognitive decline in older adults, take 40-120mg, three times a day. The supplement form of Ginkgo biloba is also called EGb-761 extract. It should be a 50:1 concentrated extract. Ginkgo biloba should be taken with meals.