With debates continuing over the value and dangers of cannabis, a study of its recent history has contemporary relevance. Its position as a useful medicine and/or dangerous drug remains in flux and issues raised by scientists, policymakers, and the media today over mental health, therapeutic potential, supply, and mode of usage are recurrent throughout its history. This paper provides an overview of a Wellcome Trust 3-year project currently in progress. The project aims to study the process whereby boundaries shift between illicit drug and licit medicine and the issues and interests that are involved in that transaction. The project, now in its third year has included a review of the literature, and archival work at the Wellcome Trust, National Archives and the World Health Organization (WHO). The bulk of the interviews have been carried out and the project is now at the writing up stage. The study is framed as a history of science and policymaking. The overall hypothesis is that the medicalization of cannabis has been an important route for changes in the environment in which the United Kingdom policy on cannabis has been made. Medicalization is defined as the introduction of medical uses and structures for the drug, as distinct from nonmedical illicit usage. Understanding that full medicalization has not been established, it seeks to examine the intervening stages/process of the transition. References