The Food and Drug Administration (FDA) for the first time approved a drug directly derived from cannabis on Monday, Epidiolex, developed by the British GW Pharmaceuticals.

Although several states have legalized the medical and recreational use of marijuana, the federal agency had yet to do so until today. Under the Controlled Substances Act, marijuana is a Schedule I drug, meaning it has a high potential for abuse and no recognized medical purpose (heroin, LSD, and ecstasy are also Schedule I drugs). A bill was introduced to the House last year to legalize the use of marijuana, but it has yet to reach the floor for vote.

The active ingredient in Epidiolex, an epilepsy medication, is cannabidiol (CBD), one of the two main chemical compounds found in marijuana. While CBD has purely medicinal purposes, the other compound, tetrahydrocannabinol (THC), is what gives marijuana users the psychoactive effects commonly associated with the plant. Epidiolex contains less than 0.1% of THC.

An FDA advisory panel recommended the approval of Epidiolex last April, specifically for the treatment of Lennox-Gastaut syndrome and Dravet syndrome, two serious and rare forms of epilepsy that appear at an early age. The agency ultimately approved the therapy for both conditions in children two years of age or older on Monday. [Read More @ Fortune]