Harry Sumnall is Professor in Substance Use at the Public Health Institute, Liverpool John Moores University, UK. He is interested in all aspects of substance use, and his funded research programmes have examined the evidence base for substance misuse prevention and the mechanisms for implementing evidence-based practice and policy. Current projects include evaluation of service models and systems for co-existing serious mental health and substance use conditions, development of interventions, and understanding how stigma affects public attitudes and support for evidence-based drug policy. He has a long-standing interest in psychedelics and entactogens, and scientific investigations into these compounds first inspired his interest in their psychopharmacology and therapeutic potential, and led him to study pharmacology as an undergraduate. Harry was a Member of the UK Government Advisory Council on the Misuse of Drugs between 2011-2019, providing recommendations on UK drug law, regulation, and policy. He was a Board Member and Past-President of the European Society for Prevention Research (2010-2019) and is currently a scientific advisor to the MIND Foundation bringing expertise on policy, education, and practice.