The line between medicines and drugs is blurred. This is due, on the one hand, to the varied applications of the substances themselves, and, on the other, to the culturally variable and historically changing ways of dealing with them. Before amphetamines became today’s “party drug”, they were used at the beginning of the 20th century to treat tiredness and concentration problems. Heroin was first marketed as an extremely potent painkiller before becoming the main substance responsible for drug deaths in the 1970s. In the 1960s, LSD was still the psychedelic miracle drug of the counterculture, which was then quickly banned in most Western countries. Today, LSD is experiencing a renaissance as a drug used to treat depression and post-traumatic stress disorder. So every medicine has the potential to become a drug – and vice versa.