Drugs controlled by the United Kingdom (UK) Misuse of Drugs Act 1971 are listed in this article.
These drugs are known in the UK as controlled drugs, because this is the term by which the act itself refers to them. In more general terms, however, many of these drugs are also controlled by the Medicines Act 1968, there are many other drugs which are controlled by the Medicines Act but not by the Misuse of Drugs Act, and other substances which may be considered drugs (alcohol, for example) are controlled by other laws.
The Misuse of Drugs Act sets out three separate categories, Class A, Class B, and Class C. Class A drugs represent those deemed most dangerous, and so carry the harshest punishments. Class C represents those thought to have the least capacity for harm, and so the Act demands more lenient punishment. In reality the potential harm has little bearing on the class, which has led to dissatisfaction with drug laws.
Being found in possession of a drug on this list is dealt with less seriously than would be if it were deemed that there is intent to supply (even without payment) the drug to others. Possession with intent to supply carries a maximum penalty of life imprisonment.
With regard to lawful possession and supply, a different set of categories apply which are set out in the Misuse of Drugs Regulations 2001 (as amended). This sets out five schedules each with their own restrictions. Schedule 1 contains substances considered by the government to have no medicinal value, such as hallucinogens, and their use is limited primarily to research, whereas schedules 2–5 contain the other regulated drugs. This means that although drugs may fall into the category of Class A/B/C, they may also fall into one of the schedules for legitimate medicinal use. For example, morphine is a Class A drug under the Misuse of Drugs Act 1971, but when lawfully supplied falls under the category of a Schedule 2 controlled drug.
Substances may be removed and added to different parts of the schedule by statutory instrument, provided a report of the Advisory Council on the Misuse of Drugs has been commissioned and has reached a conclusion, although the Secretary of State is not bound by the council's findings. This list has in practice been modified a great number of times, sometimes removing substances, but more commonly adding some; for example, many benzodiazepines became Class C drugs in 1985, and many cathinones became Class B drugs in 2010.