What’s better, Wegovy or Mounjaro?

Choosing between Wegovy and Mounjaro comes down to what you’re aiming for (weight, blood sugar, side-effect profile) and what’s available to you. Many people see strong results with both; tirzepatide can yield greater reductions for some, while semaglutide has a longer real-world track record.

Why these two drugs stand out

Wegovy and Mounjaro are often compared because they’re part of the same family of treatments known as incretin-based medicines. Both act on hormones that help control appetite and blood sugar, but they work slightly differently. Wegovy contains semaglutide, which mimics GLP-1, while Mounjaro contains tirzepatide, which targets GLP-1 and an additional receptor called GIP. This “dual action” is one reason Mounjaro has shown very strong results in trials.

How they perform in studies

Looking at trial data is helpful, though it’s only part of the picture. In the STEP programme, semaglutide 2.4 mg (Wegovy) helped participants lose on average about 15% of body weight over 68 weeks when combined with diet and exercise. The SURMOUNT studies of tirzepatide (Mounjaro) reported average losses of more than 20% at higher doses over a similar time frame. Both outperformed older treatments such as Saxenda or Orlistat by a wide margin.

Safety and side effects

Side effects are another factor in deciding what’s “better.” Because both medicines work on gut hormones, nausea, diarrhoea, and occasional vomiting are common, especially when doses are increased. For some people, these settle with time; for others, they can be difficult to manage. Tirzepatide’s dual action may cause more pronounced stomach symptoms in some cases, while semaglutide’s side-effect profile is now well documented after years of use. The right choice often depends on which medicine your body tolerates better.

Evidence for heart and metabolic health

Beyond weight loss, both medicines improve blood sugar and markers of heart health. Semaglutide has already been shown in the SELECT trial to reduce the risk of major cardiovascular events in people with overweight or obesity and established heart disease. For tirzepatide, long-term outcome trials are ongoing, so while early signals are promising, the evidence is not yet as complete. This difference may weigh heavily for those with cardiovascular risk.

Access and availability

In England, NICE has recommended Wegovy for weight management in adults with a BMI over 35 with related health problems, or in some cases with a BMI over 30. Mounjaro, as of 2025, is approved for type 2 diabetes and is under review for obesity use. That means that at present, Wegovy is more likely to be offered through NHS weight-management services, while Mounjaro may be prescribed more frequently in diabetes care.

Cost considerations

Pricing plays a role, too. NHS agreements with manufacturers are confidential, but private costs are visible and vary between providers. Wegovy and Mounjaro both represent significant expense outside the NHS, and some reports suggest that tirzepatide may be more costly in private clinics. For many people, “better” simply means what’s realistically accessible.

Individual goals and preferences

For those mainly focused on blood sugar control, tirzepatide may be the stronger choice. For those prioritising proven cardiovascular protection, semaglutide may currently be the safer bet given its established data. Lifestyle support is also essential with either drug — in trials, participants followed reduced-calorie diets and exercise plans, which helped maximise results.

Why this detail matters

The question of “what’s better” isn’t about which medicine wins on paper. Both are highly effective compared to older options, and both require ongoing commitment and monitoring. Wegovy has more established long-term safety and heart health data, while Mounjaro is showing extraordinary promise in newer studies. The better medicine is the one that aligns with your health needs, what your clinician can prescribe, and what you can tolerate and sustain.