Cannabidiol (CBD) is a chemical in the Cannabis sativa plant, also known as cannabis or hemp. One specific form of CBD is approved as a drug in the U.S. for seizure. Over 80 chemicals, known as cannabinoids, have been found in the Cannabis sativa plant. Delta-9-tetrahydrocannabinol (THC) is the most famous ingredient in cannabis. But CBD is obtained from hemp, a form of the Cannabis sativa plant that only contains small amounts of THC. CBD seems to have effects on some chemicals in the brain, but these are different than the effects of THC.