<P> The Act defines three categories of medicine: prescription only medicines (POM), which are available only from a pharmacist if prescribed by an appropriate practitioner; pharmacy medicines (P), available only from a pharmacist but without a prescription; and general sales list (GSL) medicines which may be bought from any shop without a prescription . </P> <P> The Act controls supply of the drugs it covers, but does not define any offence of simple possession . Possession of a prescription only drug without a prescription is only an offence if the drug is also controlled under the Misuse of Drugs Act 1971 and possession is thus specified as an offence . Therefore, for example, possession of a prescription only antibiotic without a prescription is not an offence . </P> <P> For description of the legal classification of medicines in the UK see the Royal Pharmaceutical Society web site, and the publication' Medicines ethics and practice' . </P> <P> The Act was introduced following problems with the off - label use of thalidomide . </P>

What is the legal classification system for medication