What Does Off-Label Mean? Off-Label Prescribing in the UK, Explained

By Matt Brindley. For UK adults. Reviewed November 2026.

If you've read about The Sinclair Method, you've probably seen the word "off-label".

It sounds technical. Maybe even a bit worrying.

It isn't complicated. And once you know what it means, a lot of the conversations with GPs suddenly make more sense.

In short

• Off-label means a doctor prescribes a licensed medicine in a way its UK licence doesn't cover: a different condition, dose, age group or way of taking it [1].
• It's legal in the UK. Doctors can do it when they're satisfied there's enough evidence it's safe and works, and they take responsibility for that decision [2].
• It isn't the same as "unlicensed". An unlicensed medicine has no UK licence at all. An off-label medicine is licensed, just not for that use [1].
• The Sinclair Method is off-label. Naltrexone's UK licence covers its daily use to help you stay stopped. The Sinclair Method uses it only on days you plan to drink, before drinking, to drink less over time [3].
• It's why many GPs say no. Off-label prescribing puts more responsibility on the prescriber, so many GPs won't do it for a use they don't know well, as the monitoring and follow-up are part of that responsibility.

What does "licensed" mean?

Before a medicine can be sold in the UK, the regulator, the MHRA (Medicines and Healthcare products Regulatory Agency), grants it a licence [1].

That licence sets out exactly what the medicine has been approved for: which condition, which dose, which age group, and how it's taken. You'll find all of it in the medicine's official product information.

So what is off-label?

Off-label is when a doctor prescribes a licensed medicine for something outside those terms [1].

The medicine itself is exactly the same. It's the same tablet, from the same box, made to the same standards.

What changes is how it's used.

Is off-label prescribing legal in the UK?

Yes.

The GMC (General Medical Council), which sets the standards for doctors in the UK, has guidance for it [2]. In plain terms, a doctor prescribing off-label must:

• be satisfied there's enough evidence or experience to show it's safe and works
• take responsibility for prescribing it, and for the monitoring and follow-up
• give you enough information to make an informed decision
• answer your questions about it "fully and honestly" [2]
• keep a clear record of why they prescribed it

It happens across medicine. That's exactly why the GMC and the MHRA have guidance on it.

Off-label vs unlicensed: what's the difference?

They often get mixed up.

Off-label: the medicine has a UK licence, but it's being used in a way the licence doesn't cover.

Unlicensed: the medicine has no UK licence at all [1]. That isn't as unusual as it sounds. Two common examples [7]:

• a medicine made up specially by a pharmacy for one person, for example without an ingredient they're allergic to (these are called "specials")
• a medicine imported from another country, where it may be licensed, but that has no UK licence

Naltrexone is a licensed medicine in the UK [3]. On The Sinclair Method, it's used off-label.

Why is The Sinclair Method off-label?

Because of how and when naltrexone is taken.

In the UK, naltrexone's licence is for supporting abstinence: taken daily, once you've stopped drinking, as part of a full treatment programme [3]. That's the way set out in NICE guidelines and the BNF (British National Formulary, the prescribing guide UK doctors work from) [4][5].

The Sinclair Method uses the same medicine differently. It's taken only on days you plan to drink, before drinking, at a time your prescriber sets. The goal is to drink less over time... or stop, if you choose to.

Interestingly, the idea of taking a medicine only on days you're likely to drink isn't new to UK guidance. NICE already recommends a related medicine, nalmefene, taken that way, for some adults who want to cut down [6]. It's a different medicine, and NICE's guidance isn't about The Sinclair Method itself.

The full picture on the two ways of using naltrexone: Should naltrexone be taken daily or before drinking?

Why do so many GPs say no?

Off-label prescribing puts the responsibility firmly on the prescriber [2]. If a GP isn't familiar with The Sinclair Method, they may not feel able to take that on. That's a reasonable position for them to hold.

It's also one of the most common things people tell us on calls: "My GP said no."

If that's you, here's what to do next: My GP said no to naltrexone

What does it mean for you?

Mostly, it means asking good questions. Whoever prescribes, you're entitled to ask:

• Why is this being prescribed off-label?
• What's the evidence?
• What are the risks for me, with my health and my medicines?
• Who will check how I'm getting on, and how often?

A good prescriber will be glad you asked.

Common questions

Is off-label prescribing safe?
The medicine is the same licensed medicine. The question is whether that use is right for you, which is why the prescriber has to weigh the evidence and your health first [2].

Is off-label the same as unlicensed?
No. Off-label means a licensed medicine used outside its licence. Unlicensed means no UK licence at all [1].

Can my GP prescribe off-label?
Yes, GPs can. Many choose not to for uses they don't know well, because they take on the responsibility for it [2].

Is naltrexone licensed in the UK?
Yes. Its UK licence covers its daily use to help people stay stopped, as part of a full treatment programme [3]. The Sinclair Method is an off-label use.

What about private routes?

If your GP says no, there are private prescribers who understand The Sinclair Method and will prescribe naltrexone off-label where it's appropriate, with the monitoring and follow-up that come with it. Here's how to do that safely: Where to buy naltrexone in the UK

If you'd like support from us

Rethink Drink is a UK coaching service built around The Sinclair Method. Our clinical team understand The Sinclair Method, and can prescribe off-label where it's appropriate for you. Our programmes include a consultation with an independent prescriber, who decides whether treatment is suitable. Clinical oversight is provided by consultant psychiatrist Professor Jonathan Chick. Any prescription is dispensed by an independent partner pharmacy. Our coaches work with you, week by week, on everything around it.

And whatever happens, you can talk to someone today. Drinkline, the national alcohol helpline, is free and confidential: 0300 123 1110.

Please look after yourself

Before you change how much you drink or start any medication, speak to your GP or a prescriber.

I really hope this post helps. If you have any questions, you can contact me here.

Matt

Sources

1. MHRA. Off-label or unlicensed use of medicines: prescribers' responsibilities. https://www.gov.uk/drug-safety-update/off-label-or-unlicensed-use-of-medicines-prescribers-responsibilities
2. General Medical Council. Good practice in proposing, prescribing, providing and managing medicines and devices: prescribing unlicensed medicines. https://www.gmc-uk.org/professional-standards/the-professional-standards/good-practice-in-prescribing-and-managing-medicines-and-devices/prescribing-unlicensed-medicines
3. Adepend film-coated tablets (naltrexone): Summary of Product Characteristics (emc). https://www.medicines.org.uk/emc/product/3559/smpc
4. NICE. Alcohol-use disorders: diagnosis, assessment and management of harmful drinking (high-risk drinking) and alcohol dependence (CG115). https://www.nice.org.uk/guidance/cg115
5. BNF (British National Formulary). Naltrexone hydrochloride. https://bnf.nice.org.uk/drugs/naltrexone-hydrochloride/
6. NICE. Nalmefene for reducing alcohol consumption in people with alcohol dependence (TA325). https://www.nice.org.uk/guidance/ta325
7. NHS Specialist Pharmacy Service. Understanding unlicensed medicines. https://sps.nhs.uk/articles/understanding-unlicensed-medicines/