Definition: Cannabinoids are a group of substances found in the cannabis plant. They can be classified into several structural classes and include compounds such as tetrahydrocannabinol (THC) and cannabidiol (CBD). Types: The main cannabinoids are THC and CBD, but more than 100 other cannabinoids have been identified. Medical Use: While the FDA has not approved the cannabis plant itself for medical use, it has approved medications containing individual cannabinoids. For example, Epidiolex (CBD) is used to treat certain rare forms of epilepsy, and Marinol (synthetic THC) helps with nausea and vomiting due to cancer chemotherapy. Research: Research is being conducted on cannabis and cannabinoids for various health conditions, including chronic pain and the symptoms of multiple sclerosis. However, cannabis is not effective for glaucoma.