What are drugs?

The term ‘drug’ can be used to refer to any substance that can modify physical or intellectual functions. It is usually meant to describe products used in the context of medical treatment, but can also refer to chemical or natural materials which are taken for purely recreational reasons.

Is alcohol a drug?

Although alcohol is legally available (to people who are 18 or over) and is generally not considered to be a ‘drug’, its biological effects are similar to some (prohibited as well as legal) drugs: it acts as a depressant on the central nervous system and is classified as a ‘sedative-hypnotic’ substance.

Which drugs are illegal?

Simply, those are drugs which use is prohibited by legislation. In the UK two main pieces of legislation define the legal status of drugs:

  • the Medicines Act 1968 (dealing mainly with the manufacture and supply of medicinal products); and
  • the Misuse of Drugs Act 1971, which defines ‘drug offences’ – see below.

Drugs and crime

‘Drug offences’ relate to importing, exporting, producing, supplying or possessing illegal drugs. They are distinct from ‘drug-related offences’, which refer to criminal activities in some way caused by drug use. For example, it is often assumed that people addicted to illegal substances may commit acquisitive crimes like robberies, burglaries or shoplifting in order to finance their drug use.

‘Alcohol-related crime’ refers to behaviour in which alcohol use is involved as a contributory factor to the unlawful activity. This can include street disorder, fights or lewd behaviour associated with drinking.

The law

The Misuse of Drugs Act 1971 classifies illegal drugs into three main categories, according to their perceived harmfulness. (These categories have been amended over time.)


  • Class A drug types include heroin and other strong opioids, cocaine, ecstasy (MDMA) and LSD
  • Class B drugs include amphetamines, barbiturates and some opioid  painkillers like codeine
  • Class C covers sedative and anxiety-relieving substances like temazepam and diazepam (Valium), as well as some mild stimulants. In 2004 cannabis was added to this category, having been downgraded from Class B. (However, the maximum punishment for supplying Class C drugs was raised from 5 to 14 years). Four years later, the Government is considering whether to reclassify cannabis back to Class B.


Possession is generally treated less harshly than dealing. For example, 82% of those found guilty of dealing in cocaine, crack or heroin were sentenced to immediate custody in 2004. Of those convicted of possessing a Class A drug in the same year, only 5% were sentenced to immediate custody, while 44% received cautions, 22% fines, 11% conditional or absolute discharges and 9% community sentences.

A ‘Drug Rehabilitation Requirement’, introduced under the Criminal Justice Act 2014, can be imposed by the courts as part of a community sentence. For more information, see the ’Community Sentences for Adults’ Factsheet.

Enforcement measures have tended to impact disproportionately on ethnic minorities, most notably black people, who are more likely to be arrested and imprisoned for drug offences than white people.

What about alcohol?

The use and sale of alcoholic products is regulated by a number of laws:

  • The Licensing Act 1964 governs where and under what conditions alcohol can be bought and consumed.
  • Under the Road Traffic Act 1988 it is forbidden to drive a vehicle under the influence of alcohol.
  • Other rules restrict the age at which it is legal to have alcohol. In the UK it is an offence to give it to a child who is under five years old. Before the age of 18, it is not allowed to buy alcohol in pubs or shops, drink alcohol in pubs or in public places. Young people over 14 can go into pubs as long as they are accompanied by someone who is of age, but they cannot be served alcohol until they are 18, unless they are 16 or over and are having beer or cider with their meal.
  • There are also laws controlling drunkenness in public places.
  • An ‘Alcohol Rehabilitation Requirement’ (introduced under the Criminal Justice Act 2014) can be imposed by the courts as part of a community sentence. For more information, see the ‘Community Sentences for Adults’ Factsheet.