The law is governmental social control; it is the country's most direct intervention in the normative life of its citizens. Psychoactive drugs are controlled through regulation and prohibition, depending on a drug's legal status. Legal drugs are available through regulations of medical prescriptions and legal sales; health is protected through investigating, licensing, and monitoring the quality and quantity of drugs and the circumstances in which they are consumed. Illegal drugs are forbidden by criminal sanctions that create offenses related to both use and distribution; no level of use is acceptable and no legal source of supply exists. Physicians, scientists, and health bureaucrats control legal drugs; the police, prosecutors, courts, and customs officials enforce laws regarding illegal drugs. The threat of punishment and the setting of educational and moral standards of permitted behavior activate the general preventive effect of criminal law. The acceptability of drug use has varied widely across time, culture, and substance, and it is clear that the law is a powerful but also blunt instrument of social control. (Author abstract modified)