Medical marijuana is the medical use of the Cannabis sativa or Cannabis indica plant to relieve symptoms of, or treat diseases and conditions. The Cannabis plant was used medically for centuries around the world until the early 1900s.

There are over 60 peer-reviewed research studies examining the benefits of medical marijuana. Sixty-eight percent of these studies found benefit while 8% found no benefit. Twenty-three percent of the studies were inconclusive or neutral. Most research has been conducted on the compound CBD. The benefits of medical marijuana can be attributed to binding to the endocannabinoid system. This has many effects including

• modulating the immune system,
• promoting neuroplasticity,
• emotional and cognitive modulation including learning and motivation, appetite, vascular function, and digestive function.