What is Semax? If you are wondering what is Semax, you have come to the right place. Semax is a nootropic (neurotransmitter) and is used to treat brain disorders. However, Semax is not approved by the FDA. To find out more about Semax, read this article. Semax is a nootropic Semax is a nootropic supplement which works by improving the blood supply to the brain. Its therapeutic properties include improving memory and learning abilities. It also stimulates neurogenesis, the generation of new nerve pathways in the brain. Semax also helps in treating various health issues, including depression and anxiety.