Arthur Christopoulos is a pharmacist and molecular pharmacologist who has made seminal discoveries of spatially distinct ‘allosteric’ drug binding sites on G protein-coupled receptors (GPCRs), the largest class of all medicinal targets. His research spans the interface of chemistry and biology with a particular focus on neuropsychiatry, cardiometabolism, pain and addiction. His research is highly cited, included in textbooks, and acknowledged via the highest honours from Australasian, United States, United Kingdom and world Pharmacological Societies, transforming the way GPCR medicines are discovered in academia and industry.