Are Ozempic and Tirzepatide the Same Medicine?

Do Ozempic and tirzepatide work through the same mechanism?

They share a family resemblance but are pharmacologically distinct. Ozempic (semaglutide) is a GLP-1 receptor agonist, it mimics one incretin hormone, which slows gastric emptying, reduces appetite and helps regulate blood sugar. Tirzepatide, sold in the UK as Mounjaro, is a dual GIP and GLP-1 receptor agonist, the only medicine of its kind currently licensed in the UK. Activating both pathways appears to produce a more pronounced effect on satiety and energy balance than GLP-1 stimulation alone, which is reflected in the trial data. So while both slow gastric emptying and reduce appetite, they do so through overlapping but not identical mechanisms. Calling them "the same" is a bit like calling a bicycle and a motorcycle the same because they both have two wheels. The basic direction is similar; the engineering is not. If you are wondering whether Ozempic is actually a tirzepatide, the short answer is no, and understanding that distinction is a useful starting point before comparing the two medicines further. If you are wondering whether tirzepatide and Ozempic are actually the same medicine, the short answer is no, and the distinction matters in practice, particularly when it comes to what each is licensed for.

Are they licensed for the same things in the UK?

This is where the difference is most consequential. Ozempic is licensed in the UK for type 2 diabetes, not weight management. The MHRA has been explicit that GLP-1 medicines should not be used for quick or cosmetic weight loss, and prescribing Ozempic for weight loss alone is off-label. The weight-loss branded version of semaglutide is Wegovy, which carries a UK weight-management licence and is the medicine NICE evaluated in its appraisal of semaglutide for obesity (NICE TA875). Tirzepatide, meanwhile, was approved by the MHRA as Mounjaro for weight management in adults with a BMI of 30 or above, or 27 or above with a weight-related condition such as high blood pressure or type 2 diabetes. NICE went on to recommend it for NHS use under TA1026. People sometimes ask whether tirzepatide is the same as Wegovy, but they are distinct medicines with different active ingredients, different licensing histories, and different trial programmes. In short: if you are looking for a medicine licensed for weight loss in the UK, Ozempic is not it. Mounjaro and Wegovy are. This matters for safety, for legitimacy of supply, and for what any prescriber can responsibly offer you.

How do the trial results compare?

Because Ozempic is not a weight-loss medicine, the most relevant comparison for anyone researching weight management is between Mounjaro (tirzepatide) and Wegovy (semaglutide 2.4mg). In the SURMOUNT-1 trial (2,539 adults with obesity, 72 weeks), tirzepatide produced average body-weight reductions of around 20–21% at the 15mg dose, as reported in the New England Journal of Medicine. The STEP 1 trial for semaglutide 2.4mg (Wegovy) showed around 15% average reduction over 68 weeks. A direct head-to-head (the SURMOUNT-5 trial, published in the NEJM in 2025) found tirzepatide produced greater average weight loss than semaglutide 2.4mg over 72 weeks. Wegovy's newer 7.2mg dose narrows that gap. Which result translates to which individual is a clinical judgement, not a marketing one; how these two medicines compare in more detail is worth reading if you're weighing up your options. The table below summarises the key factual differences.

So what is licensed for weight loss at a UK pharmacy?

At nume (at nume) the two medicines dispensed for weight management are Mounjaro (tirzepatide) and Wegovy (semaglutide), both obtained through the licensed UK supply chain. Ozempic is not something any regulated UK pharmacy should supply for weight loss, and if you encounter a seller offering it for that purpose, that is a red flag worth taking seriously. Wegovy and Mounjaro are different medicines too, and deciding which suits you is not something a website can do. It depends on your medical history, your current medicines, your BMI, and other factors a prescriber needs to review. Our prescribers at our clinical team assess every consultation personally, on the day it's submitted. If you'd like to understand which weight-loss treatment you might be eligible for, the right starting point is a consultation rather than a comparison article. Check your eligibility and a GPhC-registered prescriber will review your case the same day, your answers land on a real clinician's desk, not an automated queue.