AbstractMethamphetamine has been marketed illicitly since the 1960s. Much of the street material was illicitly synthesized. Although methamphetamine quality was variable in the past decade, it has emerged since 1978 as the only street stimulant which is likely to contain what it purports to contain. Although there is a small volume of legitimate methamphetamine still made by the pharmaceutical industry, most material analyzed by street-drug laboratories appears to have been illegitimately synthesized and not diverted. For a decade, relatively little methamphetamine was submitted to street-drug analytical labs. In recent years, although the absolute volume of methamphetamine submissions changed little, this drug made up the bulk of alleged stimulant samples submitted to such facilities because of the paucity of amphetamine submissions. Methamphetamine synthesis and use appears to constitute a small but continuing portion of the illicit drug market.