Psilocybin, as an “ester of psilocin”, is controlled as a Class A drug under the 1971 Act and has been since the Act was introduced.
Psilocybin is also placed in Schedule 1 to the Misuse of Drugs Regulations 2001. Psilocin is subject to the United Nations Convention on Psychotropic Substances of 1971, to which the United Kingdom is signatory.
As the then Crime and Policing Minister set out in his response to Question 7725, a number of drugs which have been controlled under the 1971 Act for a considerable period of time have not been subject to analysis or recent analysis of harm. The Advisory Council on the Misuse of Drugs regularly provides advice on the harms of drugs, and these are published on the gov.uk website.