What do drug classes mean in the UK?

Drug classes can be confusing, especially when a substance is also used as a medicine or its legal status has changed. In the UK, controlled drugs are grouped into Class A, Class B and Class C under the Misuse of Drugs Act 1971.

The classes help determine the maximum criminal penalties for offences involving those drugs. Class A carries the highest maximum penalties. That does not mean a Class C drug is harmless: the class alone is not a guide to whether a substance is safe for a particular person.

UK drug classification chart

The table below gives familiar examples. It is not a complete list, and some substances and preparations have additional rules.

GHB and GBL are Class B drugs. Nitrous oxide is Class C, with rules that allow legitimate uses. These are worth checking if you have come across an older classification chart.

For a particular substance, use the Home Office controlled-drugs list, which shows both its class and schedule.

Are drug classes the same as schedules?

No. Classes A, B and C relate to the legal classification and penalties. Schedules 1 to 5 concern controls on legitimate access and use, including medicines.

A controlled drug can have a lawful medical use. Codeine and diazepam, for example, appear in the classification system as well as being used in medicines. Being prescribed a medicine does not change its class. If you are unsure about your own medication, ask your pharmacist or prescriber rather than changing how you take it.

What are the maximum penalties for drug offences?

Possession and supplying or producing a controlled drug are different offences. Supplying can include giving a drug to someone else; money does not have to change hands.

An unlimited fine can be imposed instead of, or alongside, imprisonment. These are maximum penalties, not automatic sentences. The circumstances of an offence affect the outcome.

There are exceptions and specific rules. For example, possessing anabolic steroids for personal use is not an offence, although supply is controlled. See the GOV.UK drug penalties guide for the official summary.

What about temporary class drugs?

A temporary class drug order allows a substance to be controlled for up to a year while a decision is made about longer-term controls. It is a separate legal mechanism, not a permanent fourth class alongside A, B and C.

Under a temporary order, simple possession is not an offence, although police can seize the substance. Supply and production can carry a prison term of up to 14 years, an unlimited fine, or both. Old lists of temporary class drugs can be misleading because substances may since have been brought under permanent controls.

Psychoactive substances and laughing gas

The Psychoactive Substances Act 2016 covers certain substances intended to be consumed for their mind-altering effects. It is separate from the Class A, B and C system and has exemptions, including substances already controlled under the Misuse of Drugs Act.

For substances covered only by that Act, simple possession is generally not an offence outside a custodial institution. Producing, supplying, importing or exporting them can still be an offence. A substance being outside the A, B and C lists does not automatically mean it can be sold legally.

Laughing gas now needs to be considered separately. Nitrous oxide has been controlled as a Class C drug since November 2023. Possession for wrongful inhalation is illegal, while legitimate purposes such as medical and catering uses remain permitted. The Home Office nitrous oxide guidance explains the distinction.

What do drug classes mean for drug testing?

A drug's legal class and a drug test's panel are different things. A panel is the set of substances a test is designed to look for. It should not be assumed that a test covers every Class A, B or C drug.

If you need to check for a particular substance, ask whether it is included before choosing a test. Our drug testing information explains the available methods. For an employer arranging screening, our guide to choosing a workplace drug test is a useful next step.

Common questions about UK drug classifications

What class is ketamine in the UK?

Ketamine is a Class B controlled drug. For the classification of a named substance, check the official controlled-drugs list.

Are Class C drugs legal?

Class C drugs are controlled drugs. Whether possession is lawful depends on the substance and circumstances, such as lawful medical use or a specific exception. Class C does not mean freely available or safe to misuse.

Can a prescription medicine be a controlled drug?

Yes. Some medicines contain controlled drugs. Follow your prescriber's advice and raise medication questions with your pharmacist or prescriber. If a test is being arranged, ask the testing provider how prescribed medication should be recorded.

Does a drug test detect every drug class?

Do not assume so. Ask which substances the particular test covers and whether it suits the purpose of the test. You can contact our team to discuss the available testing options.