Mounjaro®
Starting from £179.99/mo
Start journey Learn moreWhat the trial evidence, licensed doses, and your situation each tell you
You've been looking at the numbers and wondering which one actually delivers
Plenty of people arrive at this question having seen headlines about Mounjaro's results and wondering whether Wegovy has been quietly left behind. It's an understandable read of the coverage — but the picture is more layered than a single percentage.
In NICE's appraisal of tirzepatide (TA1026), the committee reviewed evidence showing that tirzepatide at its highest licensed dose produced average body-weight reductions of around 20 to 21 percent over 72 weeks in the SURMOUNT-1 trial. Semaglutide 2.4 mg, the standard maintenance dose of Wegovy, produced around 15 percent in the STEP 1 trial over a similar duration. The SURMOUNT-5 trial then compared the two directly in adults with obesity and no diabetes, and if you've been reading about cases where Wegovy worked better than Mounjaro for certain individuals, that trial helps explain why individual variation matters even when tirzepatide produced the larger average loss across the group. Those are real and meaningful differences at a population level.
Where it gets more nuanced: Wegovy's newer 7.2 mg dose (approved by the MHRA in April 2026) reported around 20.7 percent average weight loss over 72 weeks in trials, narrowing the gap considerably. So the comparison between the two medicines isn't fixed; it depends on which dose of each medicine is in the frame. More on that in the section below.
How the two medicines actually differ, and where the comparison table sits
Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist: it activates two gut-hormone pathways linked to appetite regulation and blood-sugar control. Wegovy (semaglutide) activates one of those pathways, the GLP-1 receptor, making it a single-agonist. Both slow gastric emptying and reduce appetite; tirzepatide's second mechanism is the reason many researchers believe it produces larger average losses.
The side-effect profiles are similar: both are dominated by gastrointestinal effects (nausea, loose stools, indigestion and, less commonly, vomiting) most noticeable after starting or after a dose step. The MHRA's guidance on GLP-1 medicines notes acute pancreatitis as an infrequent but serious risk with this class; seek urgent medical help for severe, persistent stomach pain that spreads to the back. Both carry a Black Triangle (▼) in the UK, meaning they are subject to additional monitoring. Neither is recommended in pregnancy, while breastfeeding, or for those trying to conceive, and neither is licensed for under-18s.
One misconception worth putting to rest gently: people sometimes assume Wegovy is essentially the same as Ozempic. Wegovy and Ozempic both contain semaglutide, but Ozempic is licensed in the UK for type 2 diabetes management, not weight loss. For a fuller comparison of those two, our page on Mounjaro vs Ozempic covers the distinction clearly.
| Feature | Mounjaro (tirzepatide) | Wegovy (semaglutide) |
|---|---|---|
| Mechanism | Dual GIP + GLP-1 receptor agonist | GLP-1 receptor agonist |
| Average weight loss in trials | ~20–21% at 15 mg over 72 weeks (SURMOUNT-1, NEJM) | ~15% at 2.4 mg over 68 weeks; ~20.7% at 7.2 mg over 72 weeks |
| Head-to-head result | Greater average loss vs semaglutide 2.4 mg (SURMOUNT-5, NEJM 2025) | 7.2 mg narrows the gap substantially |
| UK dosing range | 2.5 mg to 15 mg once weekly; titrated by prescriber | 0.25 mg to 2.4 mg (standard) or 7.2 mg (higher dose) once weekly; titrated by prescriber |
| UK weight-management licence | BMI ≥30, or ≥27 with a weight-related condition | BMI ≥30, or ≥27 with a weight-related condition (7.2 mg pen: BMI ≥30 only) |
| NICE recommendation | TA1026 (December 2024, updated September 2025) | TA875 (March 2023); max 2 years, within specialist service |
Which one a prescriber would consider for you
Both medicines share the same broad eligibility shape: adults, BMI of 30 or above, or 27 or above alongside at least one weight-related condition such as high blood pressure, high cholesterol, type 2 diabetes or obstructive sleep apnoea. Lower thresholds apply for some ethnic backgrounds under UK guidance. Neither medicine suits everyone, and the trial averages tell you what happened across thousands of participants, not what will happen for you.
A prescriber weighs your full medical picture: existing conditions, medicines you're already taking (tirzepatide may reduce oral contraceptive absorption during the first four weeks of treatment and after each dose increase, which is worth discussing), your previous experience with weight-loss treatment, and your preference on how treatment is delivered. Wegovy is also available as the newly approved oral semaglutide tablet (the first oral GLP-1 licensed for weight management in the UK, approved by the MHRA in June 2026) which may suit people who'd prefer not to inject.
The Wegovy vs Mounjaro comparison page goes deeper on specific clinical factors, and if you're still forming a view, our pages exploring whether Wegovy or Mounjaro is better, what's better between Mounjaro or Wegovy from a clinical standpoint, and what's better when looking at Wegovy or Mounjaro side by side can help you build a clearer picture before your consultation. At nume, every consultation is read by a named GPhC-registered Independent Prescriber who can advise which option fits your situation, or whether either is appropriate. That's a conversation, not an algorithm. Check your eligibility and start that conversation today, there's no charge for the consultation itself.
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