Cannabis, commonly known as marijuana, weed or pot, is a natural product derived from the Cannabis sativa plant. It has been used medicinally for thousands of years. Recent legislation allowing the use of medical marijuana in over 23 US states has spurred interest in developing pharmaceutical-derived Cannabis products to treat a variety of clinical indications ranging from pain relief to epilepsy. Many products are in late stage clinical development in the US and elsewhere. This article reviews the medicinal properties of Cannabis and describes pharmaceutical-derived Cannabis products that are currently being developed for theUS market.