Medical Cannabis

medical cannabis, also called medical marijuana, herbal drug derived from plants of the genus Cannabis that is used as part of the treatment for a specific symptom or disease. Although the term cannabis refers specifically to the plant genus, it is also used interchangeably with marijuana, which describes the crude drug isolated from the plants’ leaves and flowers.

While cannabis has a long history of medical use as an analgesic (pain reliever) and antispasmodic agent, for much of the modern era there existed a general lack of awareness among scientists and physicians of its medical benefits. The discovery of the active ingredient tetrahydrocannabinol (THC) in the 1960s, as well as the discovery of a system of endogenous cannabinoid receptors and ligands in the late 1980s and early 1990s, promoted inquiry into the therapeutic potential of cannabis and its extracts and derivatives. (Endogenous substances are those produced by the body; in biology, ligands are substances that bind to receptors.) This work revealed that cannabis can provide relief from certain types of conditions, such as severe chronic pain, and led to the development of various herbal medical cannabis products.