UK cannabis patients occupy a complex policy space in which prescribing has been lawful since 2018, but the drug remains otherwise illegal. This article draws on qualitative interviews from the first UK sociological study of cannabis patient experiences. The findings demonstrate that contradictory policies; a lack of training for professionals; and the legacy of prohibitionist constructions of cannabis result in a range of harms, including inequality and stigma. We employ the concepts of ‘stigma power’ and the ‘stigma machine’ to situate these experiences within the UK's contemporary neoliberal agendas and subsequent commitment to prohibition. Patients are not passive recipients of this stigma, employing what we term concealment, (re)construction and evangelism, to resist these processes. Like many of them, we call for comprehensive professional and public education about the legality of medical cannabis. We argue that to reduce stigma and inequality, this must be accompanied by critical reforms of drug policies.