Mounjaro®
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Start journey Learn moreMounjaro vs Ozempic: the full picture on licences, mechanisms, and what this means for weight loss in the UK
You have seen both names online, but only one is licensed for weight loss here
Picture this: you have been reading about GLP-1 medicines, you have seen Ozempic everywhere from morning TV to the pharmacy shelf, and now you are wondering whether Mounjaro is simply a newer version of the same thing. It is a reasonable assumption. Both are weekly injectable medicines. Both reduce appetite. Both originate from gut-hormone research. The mechanisms, however, diverge, and so do the UK licences, which is the part that changes everything.
Ozempic is a brand of semaglutide made by Novo Nordisk. In the UK, it is licensed solely for adults with type 2 diabetes. It is not authorised here for weight management, and prescribing it off-label for that purpose is not standard clinical practice at a regulated pharmacy. The medicine that carries the UK weight-loss licence for semaglutide is Wegovy, a different product, different dose, different approval. So when people talk about the Ozempic and Mounjaro difference in the context of losing weight, they are, technically, comparing the wrong product, and if you want to understand the difference between Ozempic and Mounjaro in full, that page unpacks why the distinction matters clinically. The meaningful clinical comparison for weight loss is Mounjaro versus Wegovy.
Mounjaro (tirzepatide, made by Eli Lilly) is a dual GIP and GLP-1 receptor agonist, the only medicine of its kind licensed in the UK. It activates two appetite-related gut-hormone pathways simultaneously. Wegovy activates one. That is not a sales pitch; it is a pharmacological fact worth understanding before any clinical decision is made. The NHS medicines page for tirzepatide sets out the mechanism clearly.
What the trial evidence shows, and why Ozempic is not in it
Because Ozempic is a diabetes medicine, the weight-loss clinical trials that matter here compare tirzepatide against semaglutide 2.4mg (Wegovy's dose) rather than Ozempic's diabetes doses. The SURMOUNT-5 trial, published in the New England Journal of Medicine in 2025, ran head-to-head for 72 weeks in adults with obesity. On average, participants taking tirzepatide lost more body weight than those taking semaglutide 2.4mg. The NICE appraisal of tirzepatide (TA1026) acknowledged indirect comparisons that favour tirzepatide, while noting that Wegovy 7.2mg (approved by the MHRA in early 2026) narrows the gap at its higher maintenance dose.
Putting numbers in perspective: SURMOUNT-1 (around 2,500 adults, 72 weeks) found average weight reductions of roughly 20–21% at the 15mg tirzepatide dose. The STEP 1 trial for semaglutide 2.4mg showed approximately 15% average reduction at 68 weeks. These are trial averages, not guarantees, and individual results vary. The right question is not which headline figure is bigger, but which medicine a prescriber considers appropriate for your specific health picture.
You can explore the clinical detail behind these comparisons further, and for a structured overview of how the two medicines sit apart from each other, the page covering the key differences between Ozempic and Mounjaro is a useful reference. The short version is this: comparing Mounjaro with Ozempic for weight loss is a category error. Ozempic is not a weight-loss medicine under UK law.
| Factor | Mounjaro (tirzepatide) | Ozempic (semaglutide) |
|---|---|---|
| UK licence for weight management | Yes (BMI ≥30, or ≥27 with a weight-related condition | No) licensed for type 2 diabetes only |
| Mechanism | Dual GIP and GLP-1 receptor agonist | GLP-1 receptor agonist |
| Manufacturer | Eli Lilly | Novo Nordisk |
| Equivalent semaglutide weight-loss product | N/A | Wegovy (different dose, separate licence) |
| Average weight loss in trials (weight-management doses) | ~20–21% at 15mg over 72 weeks [SURMOUNT-1, NEJM] | ~15% at 2.4mg over 68 weeks [STEP 1, NEJM] |
| Dispensed by nume for weight loss | Yes | No |
Which is right for you, and how a prescriber works that out
If your goal is weight management and you are not managing type 2 diabetes with an existing prescription, Ozempic is not on the table. The licensed options in the UK are Mounjaro and Wegovy. Both require a prescription following clinical assessment. Neither is available to buy simply by asking; a prescriber has to judge suitability against your medical history, current medicines, BMI, and any other conditions. For a detailed look at how those two licensed options compare, the Wegovy vs Mounjaro breakdown is the place to go next.
At nume, every consultation is read by a named GPhC-registered Independent Prescriber the same day you submit it, not a bot, not an automated score. If you have questions about the mounjaro ozempic difference as it applies to your own situation (perhaps you are already prescribed Ozempic for diabetes and wondering about weight management options), that is exactly the conversation a prescriber can have with you. You can also read more about our clinical team's approach to these assessments. Treatment is dispatched the same day once approved, arriving with DPD the next working day in plain, unbranded packaging, order before noon and it can be with you the following morning.
Cost is worth a brief note too. Because the two medicines have different licences and come from different manufacturers, their price points differ. The cost comparison between tirzepatide and semaglutide covers that in full. Which suits you is a clinical decision our prescribers make with you.
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