Drug prohibition law is prohibition-based law by which governments prohibit, except under licence, the production, supply, and possession of many, but not all, substances which are recognized as drugs, and which corresponds to international treaty commitments in the Single Convention on Narcotic Drugs 1961, the Convention on Psychotropic Substances 1971, and the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances 1988.
When produced, supplied or possessed under licence, otherwise prohibited drugs are known as controlled drugs. The aforementioned legislation is the cultural institution and social fact that de facto divides world drug trade as illegal vs legal, according to geopolitical issues. The United Nations has its own drug control programme, as part of the United Nations Office on Drugs and Crime (UNODC), which was formerly called the United Nations Office for Drug Control and Crime Prevention (ODCCP), and the Commission on Narcotic Drugs is the central drug policy-making body within the United Nations system.
The International Narcotics Control Board (INCB) is an independent and quasi-judicial control organ for the implementation of the United Nations drug control conventions. It is important to note that there are several different sets of "schedules", or lists, of controlled drugs. One is the INCB schedules (four schedules numbered I-IV), while another is the United States' Controlled Substances Act schedules of controlled substances (five schedules, numbered I-V). Other countries also have different classifications and numbers of lists, such as those of the United Kingdom and Canada.
Drug prohibition law is based on the view that some drugs, notably opium poppy, coca, and substances derived from these plants, are so addictive or dependence inducing and so dangerous, in terms of potential effects on the health, morality and behaviour of users, that they should be rarely, if ever, used.
The following treaties are no longer in force, being superseded in 1961 by the Single Convention on Narcotic Drugs:
Otherwise prohibited drugs may be licensed for medical, research and industrial purposes.
Pharmaceutical companies, also known as drug companies, work under drug control licenses.
Recreational use and self-medicational use are not licensed under drug prohibition laws, although other drugs, not covered by such laws, may be legally available for this purpose. Alcohol and tobacco are notable examples of legally available recreational drugs. Aspirin is an example of a drug legally available for self-medicational purposes.
Health, moral, and behavior issues, and legal issues, are associated with alcohol and tobacco use, but these are not addressed through drug prohibition laws.
Addiction to a prohibited drug may not be considered a legitimate reason for using it, even if the drug is obtained from a licensed source, or a substitute may be provided, for example, methadone instead of heroin. Generally, however, those addicted to prohibited drugs are expected to find other ways of coping with their addictions, or to risk suffering the law enforcement penalties associated with illegal possession.
There is an extensive illegal trans-national industry supplying prohibited drugs for recreational use. Thus, while drug prohibition laws remain in force, there is perpetual law enforcement action directed against the illegal industry, which also impacts supply for self-medication.
Although it is directed against illegal recreational drugs, and not against drugs licensed under prohibition laws or against drugs beyond the scope of prohibition laws, the law enforcement is sometimes called the war on drugs.
Drug prohibition is responsible for enriching "organised criminal networks", according to some critics while the hypothesis that the prohibition of drugs generates violence is consistent with research done over long time-series and cross-country facts.