On 13 July 1931, in Geneva, the Convention for Limiting the Manufacture and Regulating the Distribution of Narcotic Drugs is signed — the League of Nations instrument capping drug production to medical and scientific needs.

The Convention introduces a system of estimates and quotas for manufacturing morphine, heroin and other narcotics, under Permanent Central Board supervision.

It complements earlier opium conventions and creates a stricter interwar regime for pharmaceutical industries.

Entry into force: 9 July 1933. For a time it was a pillar of international drug control before the 1961 Single Convention.

For narcotics law, 13 July 1931 marks the multilateral limitation of narcotic manufacture.

The official text is on the United Nations Treaty Collection / League of Nations archives.

The Convention of 13 July 1931 remains the interwar milestone limiting narcotic manufacture.

Image: Geneva; Wikimedia Commons. Cropped to 16:9.

Source consulted: 1931 Narcotic Drugs Convention. Treaty text: Convention for Limiting the Manufacture of Narcotic Drugs (UNTC).