Is Tirzepatide the Same as Ozempic?

What the trial data actually tells us about these two drugs

The clearest way to separate tirzepatide from Ozempic is to start with the clinical evidence, because that is what regulators used to licence each medicine for a specific purpose. In the SURMOUNT-1 trial, published in the New England Journal of Medicine, adults with obesity who took tirzepatide 15mg lost around 20–21% of their body weight on average over 72 weeks alongside lifestyle changes. That is the evidence base behind the UK weight-management licence for Mounjaro.

Semaglutide (the molecule inside both Ozempic and Wegovy) has its own separate evidence base. The STEP 1 trial showed roughly 15% average weight loss at the 2.4mg dose over 68 weeks. But here is where the UK licensing diverges sharply: Ozempic is dosed at up to 2mg and is authorised in the UK for blood-sugar control in type 2 diabetes. Wegovy, containing the same active ingredient at a higher 2.4mg weekly dose (and now up to 7.2mg following MHRA approval in April 2026), holds the weight-management licence. Ozempic does not. The NHS medicines page for tirzepatide and the equivalent page for semaglutide reflect this split clearly.

So asking whether tirzepatide is the same as Ozempic conflates two separate questions: the molecular question (tirzepatide versus semaglutide) and the licensing question (weight loss versus diabetes), and if you want a thorough answer to both, our page on whether Ozempic and tirzepatide are the same works through each in detail. The short answer to both is no.

Dual receptor versus single receptor, why the mechanism gap matters

Tirzepatide is the only weight-loss medicine licensed in the UK that activates both the GIP receptor and the GLP-1 receptor. Semaglutide (whether you encounter it as Ozempic, Wegovy, or the newer oral tablet) targets GLP-1 alone. Both pathways influence appetite, gastric emptying and blood-sugar regulation, but the combined action of tirzepatide appears to produce a stronger average reduction in body weight, as seen in the NICE appraisal of tirzepatide (TA1026), which notes indirect comparisons favouring tirzepatide over semaglutide 2.4mg. The SURMOUNT-5 head-to-head trial, published in the New England Journal of Medicine in 2025, confirmed this directly: tirzepatide produced greater average weight loss than semaglutide 2.4mg over 72 weeks in adults with obesity and no diabetes.

This is not a trivial distinction. It is why a prescriber considers both medicines as genuine alternatives rather than brands of the same thing. If you want to explore how the two compare in practical terms for weight management, our page on Wegovy versus Mounjaro goes into that detail. What the mechanism comparison does not change is the Ozempic position: because Ozempic runs at a lower semaglutide dose and carries a diabetes licence, it sits outside this comparison for weight-loss purposes.

The side-effect profiles also differ in pattern, though both share a GI-led character. Nausea, constipation, and changes in bowel habit appear with both. Tirzepatide's dual mechanism does not mean a harsher or gentler experience universally, it is individual, and managed through the same gradual dose-escalation approach both medicines use.

Which medicines are actually licensed for weight loss in the UK, and what nume dispenses

This page exists partly because Ozempic has become a shorthand in public conversation for all injectable weight-loss medicines. It is not. In the UK, the two medicines with a weight-management licence are Mounjaro (tirzepatide, by Eli Lilly) and Wegovy (semaglutide, by Novo Nordisk). Ozempic is a separate Novo Nordisk product, carrying a diabetes licence, and its prescribing for weight loss in the UK sits outside the licensed indication.

At nume, our prescribers assess patients for Mounjaro and Wegovy, the medicines with the evidence base and the regulatory authorisation for weight management. Neither is available without a prescription following clinical assessment; that is UK law. If you have been taking Ozempic for diabetes and are wondering whether tirzepatide is an option alongside or instead, that conversation belongs with your GP or specialist, who has your full medical history. For people considering private weight management treatment, the right starting point is a consultation. You can read about our clinical team and the way consultations work on our about us page, or go straight to start your free consultation.

Worth knowing: the cost picture also differs between Mounjaro and Wegovy, and between doses. Our page on tirzepatide versus semaglutide cost sets that out in plain terms.

Comparing tirzepatide and semaglutide: the key facts side by side

The table below summarises the factual differences between tirzepatide (Mounjaro) and semaglutide as Ozempic versus Wegovy. Numbers are drawn from the published trial data and MHRA/NICE records cited above.

Which of the two licensed options suits you is not a decision a table can make. It is a clinical one, made by a prescriber who knows your health history. Our prescribers do that as part of every consultation, if you want to explore further how the two weight-loss medicines sit against each other, the tirzepatide versus semaglutide comparison and the fuller Wegovy vs Mounjaro breakdown are useful next reads. For switching questions (say, moving from one to the other) the washout period guidance is worth reviewing before any consultation.