Mounjaro®
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Start journey Learn moreOzempic, Wegovy and Mounjaro: what the UK licences actually say, and what your options really are
The myth worth correcting first: Ozempic is not a weight-loss medicine in the UK
A lot of people arrive at this question having seen Ozempic discussed in the press alongside Mounjaro and Wegovy as if they are interchangeable weight-loss treatments. They are not. Ozempic and Wegovy both contain semaglutide, made by Novo Nordisk, but they carry different UK licences issued by the MHRA. Ozempic is authorised for the management of type 2 diabetes. Wegovy is authorised for weight management in adults with a BMI of 30 or above, or 27 and above with at least one weight-related condition. A prescriber working within UK law prescribes a medicine for its licensed indication. Ozempic for weight loss falls outside that boundary.
This is not a technicality. The NHS medicines information for semaglutide sets out both products clearly and distinguishes their uses. If you have been offered Ozempic from a seller claiming it treats obesity, that is a red flag worth taking seriously, the MHRA has warned repeatedly about medicines supplied outside the licensed supply chain, and reporting suspect sellers via the Yellow Card scheme helps protect other patients.
So: you cannot switch from Mounjaro to Ozempic for weight loss through any legitimate UK clinical route. What you can do is discuss switching to Wegovy, which is the correct licensed comparator.
How Mounjaro and Wegovy compare, so you can have an informed conversation with a prescriber
Both medicines reduce appetite and slow gastric emptying, but they do so differently. Mounjaro (tirzepatide) activates two gut-hormone receptors: GIP and GLP-1. Wegovy (semaglutide 2.4mg) acts on GLP-1 alone. In the SURMOUNT-5 trial, published in the New England Journal of Medicine in 2025, tirzepatide produced a greater average body-weight reduction than semaglutide 2.4mg over 72 weeks in adults with obesity. The head-to-head results favour tirzepatide, though the gap narrows at the newer 7.2mg Wegovy dose approved by the MHRA in 2026. You can review the trial data side by side if the numbers matter to your decision.
The table below covers the facts most relevant to anyone considering a switch.
| Feature | Mounjaro (tirzepatide) | Wegovy (semaglutide) | Ozempic (semaglutide) |
|---|---|---|---|
| UK licence for weight management | Yes (MHRA/NICE TA1026) | Yes (MHRA/NICE TA875) | No, diabetes only |
| Active ingredient | Tirzepatide (dual GIP + GLP-1) | Semaglutide 2.4mg (GLP-1) | Semaglutide 0.5–2mg (GLP-1) |
| Route | Once-weekly injection | Once-weekly injection | Once-weekly injection |
| Average weight loss in trials | ~20–21% at 15mg (SURMOUNT-1, NEJM) | ~15% at 2.4mg (STEP 1, NEJM); ~20.7% at 7.2mg | Not a weight-loss comparator |
| Available through nume | Yes, subject to clinical suitability | Yes, subject to clinical suitability | No |
A fuller breakdown of how the ingredients differ is covered on the Mounjaro vs Wegovy ingredients page.
If you are considering a switch, what does that process actually look like?
Switching between weight-management medicines is not like changing a brand of paracetamol. Your prescriber will want to know why you are thinking about it (tolerability, results, cost, or something else) because the reason shapes the recommendation. Someone who stopped tolerating Mounjaro's GI effects may find Wegovy's profile similar enough that a different approach altogether is worth discussing. Someone who has done well but wants to try a different mechanism has a different conversation to have.
At nume, every repeat order and every change request goes through a same-day clinical review by a GPhC-registered independent prescriber. If you have a question about whether switching makes sense in your specific situation, the Mounjaro to Wegovy switch page goes into more detail on how that transition works in practice. You can also read more about the reverse question if you previously used a diabetes medicine and are now exploring your weight-management options.
Which medicine suits you is a clinical decision our prescribers make with you, not one that belongs in a search result.
What IS available through a legitimate UK private prescription for weight management
To be direct: if you want a legal, clinically supervised private prescription for weight management in the UK, the options are Mounjaro and Wegovy. Both are dispensed by nume's GPhC-registered pharmacy (registration number 9012878, verifiable on the GPhC register). Both require an assessment; a prescriber decides suitability based on your BMI, your health history, any other medicines you take and your reasons for seeking treatment. You can check your eligibility through a free consultation, no commitment, no subscription, and the whole thing is reviewed by a real clinician the same day you submit it.
If you are weighing up the cost side of the decision, the cost comparison between the two is worth reading before your consultation. And if you want a broader picture of weight-loss options, the treatment overview covers the full landscape.
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