Ginkgo biloba, commonly known as ginkgo or gingko also known as the maidenhair tree, is a species of tree native to China. It is the only living species in the order Ginkgoales, which first appeared over 290 million years ago. Fossils very similar to the living species, belonging to the genus Ginkgo, extend back to the Middle Jurassic approximately 170 million years ago. The tree was cultivated early in human history and remains commonly planted.

Ginkgo has been used in traditional Chinese medicine since at least the 11th century C.E. Ginkgo seeds, leaves, and nuts have traditionally been used to treat various ailments, such as dementia, asthma, bronchitis, and kidney and bladder disorders. Flavonoids and terpenoids, which are chemicals with strong antioxidant properties, are abundant in ginkgo. Antioxidants work to reduce or eliminate the harmful effects of free radicals.