Dear Umesh,
Many people say it’s illegal for cannabis patients to smoke their prescribed cannabis. Can I ask under which law the police could bring a prosecution?
Oddly enough, the answer to this question is relatively straightforward once you understand the technical language and legal nuances involved. Let’s break it down step by step by defining what is legal and what is not under UK law.
The Misuse of Drugs Act 1971 (MDA)
Under the Misuse of Drugs Act 1971, cannabis (including the plant, resin, and THC-containing products) is classified as a Class B controlled drug.
Possession of a Class B drug can result in up to 5 years’ imprisonment, an unlimited fine or both. More serious offences, such as possession with intent to supply, supplying, producing, or importing/exporting, carry penalties of up to 14 years’ imprisonment.
The MDA classifies drugs according to perceived harm, which in turn determines police powers and criminal penalties:
- Class A (most serious): heroin, cocaine/crack, MDMA (ecstasy), LSD, Possession: up to 7 years’ imprisonment, Supply/production: life imprisonment
- Class B: cannabis (note: cannabis, not medical cannabis or CBPMs), amphetamines (speed), ketamine
- Class C: diazepam and some anabolic steroids
Important to know: A drug’s Class is about criminal prosecution and penalties.
The Misuse of Drugs Regulations 2001 (MDR)
A significant legal change came into effect on 1 November 2018, when amendments were made to the Misuse of Drugs Regulations 2001. These changes allowed Cannabis-Based Medicinal Products for Use in Humans (CBPMs), often referred to as medical cannabis, to be prescribed under strict conditions. (let’s think of them as a new category of medication)
Under these regulations:
- Cannabis remains a Class B drug
- Cannabis-based products were moved from Schedule 1 to Schedule 2, which now became a CBPM as long as certain provisions were met.
A Schedule 2 controlled drug may be lawfully prescribed, possessed, and supplied under tightly controlled circumstances, even though it remains a Class B drug.
What makes cannabis a legal CBPM?
For cannabis to qualify as a Schedule 2 CBPM, all of the following conditions must be met:
- Controlled production standards
The cannabis must be cultivated, manufactured, and quality-assured to pharmaceutical standards. - Strict prescribing and patient criteria
Only doctors on the GMC Specialist Register may prescribe CBPM, and only to eligible patients. (Criteria applies) - Approved routes of administration
Permitted forms include oils, capsules, and vaporised preparations. Smoking is explicitly prohibited. UK regulations state that a person “shall not self-administer” a CBPM by smoking.
Important to know: A drug’s Schedule determines whether it may be used for medical purposes.
What happens if the rules are broken?
If any of the above conditions are not met—for example, if a prescribed CBPM is smoked—the product loses its Schedule 2 status and effectively reverts to Schedule 1, meaning it has no recognised medical use.
Crucially:
- It still remains a Class B drug
- It therefore becomes illegal to possess or use
- The individual may be liable to prosecution
Before and after the 2018 change
| Before 2018 | After 2018 | |
|---|---|---|
| Class (MDA 1971) | Class B | Class B |
| Schedule (MDR 2001) | Schedule 1 (no medical use) | Certain CBPM moved to Schedule 2 |
| Doctors | Could not prescribe | Specialist doctors may prescribe CBPM |
| Pharmacies | Could not dispense | May lawfully hold and dispense CBPM |
| Patients | Could not lawfully possess | May possess only their prescribed product |
The key distinction: Class vs Schedule
Put simply:
- Class = criminal enforcement
- Schedule = medical permission
In 2018, the law did not legalise cannabis generally. Instead, it created a narrow medical exemption for specific cannabis-based medicinal products, allowing them to be used as medicines under strict regulation.
Which brings us back to the original question: Under what law could the police bring a prosecution?
As we have determined, if prescribed cannabis is not being consumed via its approved route of administration, it is no longer a Schedule 2 controlled drug. It loses its exemption and reverts to being a Class B drug under the Misuse of Drugs Act. So if the police catch you smoking your prescribed cannabis flower, this is how a prosecution may come about.
Ed note: This article is provided for general information only. It is not legal advice and should not be relied on as such.
