Cannabinoids have surely been one of the most widely self-administered drugs other than caffeine. The U.S. FDA recently approved one cannabinoid-based drug whose active pharmaceutical ingredient (API) is cannabidiol (CBD). The long history of individual use of cannabis for a wide range of conditions has sparked great interest in other uses of CBD, in ethical drugs and botanical supplements as well as in foods and nonprescription wellness products. CBD may be sourced from cannabis plants but can also be prepared synthetically, the topic of this review.