Chemical innovation and digital technologies are transforming UK, regional and international markets for psychoactive substances. This project investigates the drivers of change and how these influence current and future structures, access and trends in illicit drug markets, with a particular focus on supply side actors. The project analyses the appropriateness and impacts of the dominant drug policy approach (criminalisation) and through comparative case study work, explores if and how decriminalisation and legal regulation experiments are improving the effectiveness and evidence base of drug control strategies. The research provides practitioners, academics and policy makers with knowledge of market trends and policy options informed by the ‘lived experience’ of individuals interacting in drug markets. This is supported by a suite of online interdisciplinary professional development courses that disseminate key insights into new developments.