Active components in Ginkgo biloba extract, called flavonoids, provide a potent antioxidant and free radical scavenging action which may be the basis of the herb's cognition-enhancing, protective effects. Ginkgo biloba extract improves blood circulation in the brain, increases oxygen and nutrient supply to the central nervous system, protects against oxidative damage of nerve cells and has been found to be clinically effective in improving working memory in healthy individuals.