Why is medical cannabis an unlicensed medicine in the UK?

Unlicensed sounds alarming and mostly is not, but it does change several practical things: who carries responsibility, what information comes with the medicine, and why the same product can stop being available.

What a medicine licence actually is

A marketing authorisation is a regulator's decision about one specific product: this formulation, made by this manufacturer, for these uses, at these doses. The MHRA grants it after assessing quality, safety and efficacy data.

Once granted, a great deal follows automatically. The product carries an agreed patient information leaflet, its manufacturing is subject to defined standards, and liability for a properly used licensed medicine sits substantially with the manufacturer.

Three cannabis-based medicines have been through that process in the UK. The rest have not, which is a statement about paperwork and commercial decisions rather than a verdict on the products themselves.

Why so few cannabis products are licensed

Because licensing requires a company to run the trials and file the dossier for each specific product, and for whole-plant preparations that is expensive, slow and difficult to design.

A licence application needs consistent, characterised product and trial evidence for a defined indication. Preparations derived from whole plant material vary between cultivars and between harvests, which makes both the manufacturing standard and the trial design harder than for a single purified molecule. The one purified cannabinoid liquid that is licensed in the UK is licensed precisely because it is a single molecule with trial data behind it.

So the position is not that unlicensed products have failed an assessment. Most have never been submitted for one.

What a special is

A special is an unlicensed medicine manufactured or imported to meet the special clinical needs of an individual patient, on the order of an authorised prescriber. Regulation 167 of the Human Medicines Regulations 2012 is the provision that permits it.

The mechanism is not unusual and not specific to cannabis. Specials are used across UK medicine wherever a licensed product does not meet a particular patient's need: a liquid version of a tablet for someone who cannot swallow, a formulation without a particular excipient, a medicine licensed abroad but not here.

MHRA guidance sets out what must be true before one is supplied. The central condition is that there is a special clinical need which no licensed product meets, and that a prescriber has judged this for the individual patient.

What it changes for you

Four practical things, none of which is a reason on its own to decline treatment, and all of which are worth knowing before you start.

• Responsibility. The prescriber carries more of it than with a licensed medicine, which is why the law restricts initiation to specialists and why a proper assessment takes time.
• Information. There is no MHRA-approved patient information leaflet of the kind licensed medicines carry. Your clinic and pharmacy should tell you what you would otherwise read there.
• Continuity. A particular preparation can become unavailable, and an equivalent is not always straightforward. This is the most common practical frustration patients report.
• Reporting. Suspected side effects should be reported through the MHRA Yellow Card scheme, which matters more for unlicensed products because there is less accumulated data.

Side effects themselves are covered in What are the side effects of cannabis-based medicines?

Unlicensed is not the same as off-label

The two get used interchangeably and mean different things. Off-label is a licensed medicine used outside the terms of its licence. Unlicensed is a product with no UK licence at all.

A licensed cannabis-based medicine prescribed for a condition outside its licensed indication would be off-label use. A product with no marketing authorisation is unlicensed regardless of what it is prescribed for. Both are lawful, both shift responsibility to the prescriber, and only the second requires specialist initiation for cannabis.

Both terms have glossary entries: unlicensed medicine, off-label and special.

What to do with this

Nothing on this page decides anything about your own case. What decides it is an assessment by a specialist who has seen your records, and the useful preparation is your diagnosis, the treatments you have already tried, and what happened with each.

If continuity of supply matters to you, it is a fair question to ask a clinic before you start rather than after. The consultation itself, and what happens after it, is set out in What is the process to get a medical cannabis prescription?

Patient guide · Written by the Flora House editorial team · Last reviewed: 8 September 2026