Drug control

Drug control refers to the interlocking system of international treaties and the national statutes enacted to implement them, together determining which substances are subject to restriction and on what terms.

The foundation is three United Nations conventions: the Single Convention on Narcotic Drugs (1961), the Convention on Psychotropic Substances (1971), and the Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances (1988). Each creates schedules carrying minimum obligations for signatory states.

The Commission on Narcotic Drugs (CND) is the principal UN body that proposes changes to those schedules. The International Narcotics Control Board (INCB) monitors whether states are meeting their treaty commitments.

What it means in practice

The treaties establish a floor of control, not a uniform rule. A substance listed under a treaty schedule must be subject to at least the minimum controls that tier specifies — licensing requirements for manufacture and supply, record-keeping, restrictions on prescribing — but countries may apply stricter measures.

A substance enters the international schedules through a formal WHO Expert Committee on Drug Dependence review followed by a CND vote. The process is slow and applies only to substances already prominent enough to reach the committee's agenda. Many newer compounds are scheduled by national action alone, with no corresponding international listing.

Analogue provisions in several jurisdictions extend controls to compounds that are structurally similar to listed substances, reaching beyond named entries before any formal scheduling review has occurred.

How jurisdictions vary

The international schedule number for a substance does not travel. A tier that represents the most restrictive level in one system may correspond to ordinary prescription controls in another, and treaty schedule numbers differ from domestic schedule numbers in most countries.

The United States Drug Enforcement Administration uses a five-tier schedule, where Schedule I carries the agency's finding of no accepted medical use and high abuse potential. The United Kingdom's Misuse of Drugs Act 1971 uses three classes (A, B, and C) cross-cut by five schedules that determine what is permissible for research and medicine.

Implementation also diverges in softer ways. The Netherlands operates a formal tolerance policy for cannabis retail, permitting conduct the law still nominally prohibits. Portugal decriminalised personal possession of all controlled substances in 2001, redirecting enforcement toward administrative responses while leaving supply offences in place. These are national decisions within the latitude the treaties allow.

What is contested

The scheduling criteria used in the international system — including the phrase no currently accepted medical use — are legal determinations, not scientific verdicts. When a substance carries that designation, it describes a status the relevant authority has assigned; it does not reflect a conclusion drawn from the clinical trial record.

The practical tension has surfaced in scheduling history. Cannabis was listed in both Schedule I and Schedule IV of the 1961 convention, the latter tier reserved for substances deemed particularly dangerous with minimal therapeutic value. In December 2020, the CND voted to remove cannabis from Schedule IV while retaining it in Schedule I, a change that reflected accumulated clinical research without resolving domestic scheduling debates in most member states.

Scope and currency

This entry describes the international drug control framework as of August 2026 and is not legal advice. What these treaties and domestic classifications mean for any individual depends entirely on the law of the jurisdiction they are in, which this page cannot determine.

For the legal status of a specific substance in a specific country — with its own source and date — see the Legal status section on that substance's page.