Therapeutic substances, their development, testing, application and effects, have in recent years become a central topic of the history of medicine, history of science, and science and technology studies. This paper provides an overview of the literature on this topic through the four-fold perspective of individual substances, industry, patients, and regulation. It introduces the recently established, DFG-funded research network "Pharmaceuticals in the 20th Century" and sketches current methodological approaches to the history of therapeutic substances. At present it appears to be particularly promising to adopt an approach which uses substances or groups of substances as a heuristic device for exploring their complex networks and interdependencies.