The treatment of medical conditions with cannabis and cannabinoid compounds is advancing. Although there are numerous reports related to the genetic variations of the cannabinoid receptor, a lack of studies that examine the relationship between other pharmacogenetic markers and health outcomes currently exists. Herein, we advocate for the legalisation of marijuana in the United States in order to perform more randomised controlled trials to help elucidate the role of other pharmacogenetic targets and cannabis for use in clinical practice.