Why People Ask Whether Mounjaro Is Better Than Ozempic — and What the Evidence Actually Shows

Is Ozempic even approved for weight loss in the UK?

No. This trips up a lot of people. Ozempic and Wegovy both contain semaglutide, made by Novo Nordisk, but they carry different UK licences. Ozempic is approved by the MHRA for type 2 diabetes management. Wegovy is the formulation licensed for weight management in adults with a BMI of 30 or above, or 27 or above alongside a weight-related health condition. Prescribing Ozempic specifically for weight loss would be off-label use, and the NHS medicines page for semaglutide is clear on the distinction between the two products and their separate indications.

The question "is Mounjaro better than Ozempic?" is therefore a bit like comparing two cars with different engines and different road classifications. The search query makes sense (Ozempic is the most recognised name in this space) but the clinical comparison that matters is Mounjaro versus Wegovy. That is the one with direct trial evidence, and it is covered in detail on our Mounjaro vs Ozempic overview page. For the full weight-loss head-to-head, including mechanism and results data, the tirzepatide versus Ozempic comparison also works through the science.

How does Mounjaro's mechanism differ from semaglutide's?

Mounjaro (tirzepatide) activates two gut-hormone receptors: GLP-1 and GIP. Wegovy and Ozempic act on GLP-1 alone. This dual action is why tirzepatide is sometimes described as the more sophisticated of the two approaches, GIP activation adds a second route for appetite suppression and metabolic signalling that a single-agonist drug does not have. The practical result, borne out in the trial data, is that the average weight loss achieved with tirzepatide tends to exceed what semaglutide produces at its standard maintenance dose.

That said, mechanism is not destiny. Individual responses vary considerably. Some people lose more on semaglutide; some find the side-effect profiles differ in ways that matter to them day-to-day. A prescriber looks at your full health picture, not just the trial averages.

Both medicines slow gastric emptying and reduce appetite, both require a reduced-calorie diet and increased physical activity alongside treatment, and neither is recommended during pregnancy, breastfeeding, or when trying to conceive. Neither is licensed for anyone under 18.

What do the trial numbers actually show?

The clearest direct evidence comes from SURMOUNT-5, a 72-week open-label trial comparing tirzepatide with semaglutide 2.4 mg in adults with obesity but without type 2 diabetes. Tirzepatide produced greater average weight reduction. That finding was published in the New England Journal of Medicine in 2025 and is referenced in NICE's appraisal of tirzepatide (TA1026), which notes that indirect comparisons also favour tirzepatide.

The comparison table below sets out the headline figures across the key trials. Note that SURMOUNT-1 used tirzepatide and STEP 1 used semaglutide, so they are separate studies, SURMOUNT-5 is the only head-to-head.

Wegovy's newer 7.2 mg dose narrows the gap) the MHRA approved it in early 2026 and trial data at that strength reported around 20.7% average loss. The comparison is still moving. For a more detailed breakdown, the Mounjaro versus Wegovy page covers the 7.2 mg picture specifically.

So which one should I take?

Honest answer: that is not a question this page can settle for you, and any website claiming otherwise is overstepping. Both Mounjaro and Wegovy are prescription-only medicines requiring clinical assessment before a prescriber can issue a prescription. The right choice depends on your BMI, existing health conditions, any other medicines you take, your tolerance of side effects, and clinical judgement your GP or prescriber applies to the full picture.

What we can say: if you are specifically asking about Ozempic for weight loss, it is worth knowing that sourcing it without a valid prescription from an unverified seller is both legally risky and, according to MHRA warnings, potentially dangerous, fake pens have caused real harm. The safe-supply context page covers that in more detail.

At nume, a named GPhC-registered prescriber reads your consultation the same day, not an algorithm, not a queue. There is no subscription and no auto-renewal; every repeat order gets a fresh clinical look. If you want to find out whether Mounjaro or Wegovy suits your situation, the place to start is a free eligibility consultation. You can also read about why some patients and clinicians favour tirzepatide over semaglutide for a fuller picture of the clinical reasoning. Our clinical team reviews every case personally. Worth a look before you decide.