Dr. Wacker is a structural pharmacologist who specializes in determination of x-ray and crystal structures of membrane protein drug targets such as G protein-coupled receptors (GPCRs) and solute carrier transporters (SLCs). He further characterizes the actions of both clinical and illicit drugs using in vitro assays and structural methods, and he develops novel tool compounds and drugs for a variety of pathologies. He has determined structures of opioid, serotonin, dopamine and other receptors, and a major focus of his research has been to develop a molecular understanding of psychoactive drugs. In this context he has published several studies related to the actions of psychedelic drugs, including structures of LSD-bound serotonin receptors.