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Start journey Learn moreOzempic, Wegovy, Mounjaro: what each medicine actually is and which ones are licensed for weight loss in the UK
The misconception: people assume Ozempic and tirzepatide are the same thing, they are not
This confusion is understandable. Ozempic, Wegovy, Mounjaro and the newer Wegovy tablet have all been discussed together in news stories about weight-loss injections, and the names blur. The most common mix-up is treating "Ozempic" as a generic term for any GLP-1 medicine, or assuming it contains tirzepatide. Neither is true.
Ozempic contains semaglutide, a GLP-1 receptor agonist. Tirzepatide is a distinct molecule that activates both GIP and GLP-1 receptors, and is sold in the UK exclusively under the brand name Mounjaro. These are not interchangeable names; they describe different drugs with different mechanisms and different clinical trial programmes.
The practical consequence: if someone tells you they are taking "Ozempic for weight loss", they are almost certainly taking Wegovy (the weight-management-licensed version of semaglutide) or Mounjaro (tirzepatide). Ozempic itself is licensed by the MHRA for type 2 diabetes, not weight management, and it is not something a UK prescriber can lawfully issue for that purpose. That distinction is not a technicality. It shapes the dose, the clinical monitoring, and whether the prescription is appropriate at all.
If you have seen the question phrased as is Ozempic a tirzepatide, the short answer is no, they share a therapeutic category but nothing else.
Semaglutide and tirzepatide side by side: the facts that actually matter for weight loss
Since the question sits at the heart of how these medicines compare, it is worth being precise about what each one does and what the evidence shows.
| Feature | Semaglutide (Wegovy) | Tirzepatide (Mounjaro) |
|---|---|---|
| Molecule type | GLP-1 receptor agonist | Dual GIP and GLP-1 receptor agonist |
| UK brand for weight loss | Wegovy | Mounjaro |
| UK weight-loss licence | Yes (NICE TA875) | Yes (NICE TA1026) |
| Average weight reduction in trials | ~15% over 68 weeks (STEP 1, NEJM) | ~20–21% over 72 weeks (SURMOUNT-1, NEJM) |
| Head-to-head evidence | Tirzepatide produced greater average loss in the SURMOUNT-5 open-label trial (72 weeks, 751 adults with obesity, published NEJM 2025) | |
| Ozempic: licensed for weight loss? | No, Ozempic is semaglutide licensed for type 2 diabetes only | |
The SURMOUNT-5 results are the strongest head-to-head data available. They do not mean tirzepatide is right for everyone: individual response, medical history and tolerability all shape what a prescriber will recommend. You can read a fuller breakdown on our semaglutide or tirzepatide comparison page or explore which performs better across different measures.
Both medicines share a GI-led side-effect profile: nausea, constipation, indigestion and fatigue are the most commonly reported, typically settling after the first few weeks or after a dose increase. Both are once-weekly subcutaneous injections stored in the fridge, most people keep their pen in the fridge door alongside everyday items and simply take it out on the same morning each week. The Wegovy tablet, approved by the MHRA in June 2026, offers a needle-free daily option for those who prefer it; more on that below.
What IS licensed for weight management in the UK, and what nume offers
Two medicines currently hold a UK weight-management licence that a private prescriber can issue for eligible adults: Wegovy (semaglutide) and Mounjaro (tirzepatide). Ozempic is not one of them. At nume, our GPhC-registered pharmacy (registration 9012878) dispenses both Wegovy and Mounjaro for weight management, alongside the newer oral semaglutide (Wegovy tablets) approved in June 2026 as the UK's first licensed oral GLP-1 weight-loss medicine.
Eligibility for either injection broadly requires a BMI of 30 or above, or 27 or above alongside a weight-related condition such as high blood pressure, raised cholesterol or obstructive sleep apnoea. Lower BMI thresholds apply for some ethnic backgrounds under UK clinical guidance. Whether you are a better fit for semaglutide or tirzepatide is a clinical decision, shaped by your health history and how your body responds to treatment.
On the weight-loss treatments overview you can see both options clearly explained. If cost context matters to your decision, this page compares the two on price. And for the injection-versus-injection question in more depth, Wegovy versus Mounjaro covers the clinical picture thoroughly.
Which suits you is a clinical decision our prescribers make with you, not something any comparison article, including this one, can answer. A question our prescribers hear most weeks is some version of "which one should I choose?" The honest answer is always: start the consultation, and the right one becomes much clearer.
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