5. c. 46) is an UK act of Parliament which changed drug addiction, which up to then was treated within the medical profession as a disease, into a penal offence.

The former was the view held by the then Assistant Under Secretary of State, Malcolm Delevingne.

[2] In January 1921 the Home Secretary gave 40 days' notice of his intention to issue controls over: The act also said that the export, import, sale, distribution or possession of barbiturates, had to be licensed or authorised by the Home Secretary.

This proviso also applied to dilutions of cocaine and morphine, as defined in the lower limits set by the Hague Convention.

The Home Office, in consultation with the Ministry of Health, as a result of this Act, produced a series of memoranda for doctors and dentists to explain the requirements of the Act.