Cannabis sativa has a long history as a medicinal plant, likely dating back more than two millennia (Russo et al., 2007). It was available as a licensed medicine in the United States for about a century before the American Medical Association removed it from the 12th edition of the U.S. Pharmacopeia (IOM, 1999). In 1985, pharmaceutical companies received approval to begin developing Δ9-tetrahydrocannabinol (THC) preparations—dronabinol and nabilone—for therapeutic use, and as a result, cannabinoids were reintroduced into the armamentarium of willing healthcare providers (Grotenhermen and Müller-Vahl, 2012).