Professor Gerry Stimson is a public health social scientist, emeritus professor at Imperial College London, and honorary professor at London School of Hygiene and Tropical Medicine. He was formely co-editor-in-chief of the International Journal of Drug Policy, director of the Centre for Research on Drugs and Health Behaviour of Imperial College London, and executive director of the International Harm Reduction Association. Gerry is a director of Knowledge-Action-Change (K-A-C), a public health events and consultancy company.