Methadone, today's mainstay of treatment for opioid addiction, was originally synthesized in Germany, in 1937, after the Allies cut off their supplies of imported opium. It was developed as a morphine substitute for pain relief purposes.

It was first used as a long-acting painkiller for severe chronic pain. It was not until about 1950 that it was first used to treat the withdrawal symptoms in addicts being taken off heroin or morphine.