Cannabis Social Clubs (CSCs) are non-profit regulatory models where cannabis is produced and distributed among a closed circuit of adult cannabis users. Originating in Spain, CSCs now operate globally in different socio-political contexts and under different legal regimes. This paper argues that the CSC phenomenon is a bottom-up process arising from grassroots initiatives. Unlike Spain, Uruguay, Belgium and the USA, the UK currently offers no legal space for the operation of CSCs, yet the UKCSC movement is becoming increasingly active. Taking a comparative approach, the paper will consider how informal de facto regulatory systems can embed, facilitating formal de jure drug policy regimes. Exploring the CSC model specifically has broader implications for the regulation of psychedelics and other controlled psychoactives, since the process of bottom up law making has the potential to legitimate and transform drug policies. As well as exploring how contentious collective action by individuals and CSCs can affect change, this paper draws on case law from other jurisdictions. It considers the potential of the UK judiciary to influence drug policies relating to the CSC movement and beyond. The paper recognises the crucial importance of political power in drug policy design and it questions whether common sense ontologies, the experiential knowledge and engagement of cannabis users and their implicit underlying normative values can challenge traditional structures of power. Ultimately, the paper draws lessons from the CSC model to create better drug policy solutions for society as a whole.