Ginkgo biloba is the oldest living species of tree on Earth, having existed virtually unchanged for over 200,000,000 years. The ginkgo leaf is a rich source of flavone glycosides, bioflavonoids which deliver potent antioxidant protection. The nutrients in ginkgo extract have also been shown through extensive research to support blood vessel integrity, which is particularly important for the fine capillaries in the brain. Source Naturals Ginkgo-24™ provides a purified 24% extract of ginkgo flavone glycosides from concentrated premium quality ginkgo leaves.