Ginkgo biloba (ginkgo) is derived from the leaves of the ginkgo biloba tree and is available as a supplement. This herbal remedy is claimed to help with several medicinal uses, but most people use it to improve memory and overall mental health. As with many natural products, there are possible side effects with ginkgo biloba. Some of the common side effects seen with this supplement include stomach upset, dizziness, and headaches. Prior to taking ginkgo biloba, make sure to talk to your healthcare provider about your medical history and any other medicines you are taking (including vitamins and herbal supplements).