The past few years have witnessed a burgeoning global interest in the development of therapies related to cannabis (Cannabis sativa L.) and its components, including cannabidiols (CBD) and other active constituents of cannabis. Aman Khera, Barry J. Dussault Jr and Henry J. Riordan at Worldwide Clinical Trials summarise the recent trends in clinical trials and point out the most common and salient regulatory and operational pitfalls in an effort to overcome shifting regulatory challenges inherent in the conduct of controlled clinical trials of cannabis-related drug products.