Prior to the outlawing of cannabis in 1937, major pharmaceutical companies produced a wide variety of cannabis-based medicines, but cannabis has actually been used as a medicine for thousands of years. Although it has a long history, the recent discovery (1992) of the body's widespread endocannabinoid system (ECS) has thrust cannabis back into the limelight again as a viable medicine.

In 2012 over 2.5 million prescriptions were written for medical marijuana in the United States. CBD and THC are both cannabinoids found in cannabis. However, while THC produces a "high" in the user, CBD does...