Is Mounjaro better than Wegovy?

Mounjaro (tirzepatide) and Wegovy (semaglutide) are both effective; some studies show larger average weight loss with tirzepatide, but individual response, side-effects, access, and clinical goals matter. The “better” choice is the one that fits your health needs and tolerability after a clinician review.

Two medicines, two mechanisms

Wegovy and Mounjaro both belong to a family of medicines that mimic natural gut hormones involved in appetite and metabolism. Wegovy contains semaglutide, which activates the GLP-1 receptor. Mounjaro contains tirzepatide, which activates not just the GLP-1 receptor but also another receptor called GIP. By targeting two pathways instead of one, tirzepatide appears to provide an extra boost in controlling appetite and regulating blood sugar.

What the trials have shown

Evidence from large clinical studies helps draw a clearer comparison. In the STEP trials, semaglutide 2.4 mg (Wegovy) led to an average 15% body weight reduction over 68 weeks when combined with diet and exercise. In the SURMOUNT trials, tirzepatide achieved average losses of over 20% at higher doses, again with lifestyle support. Published in The New England Journal of Medicine and The Lancet, these results suggest that tirzepatide can lead to greater average weight loss, though both medicines outperformed other options such as Saxenda or Orlistat by a wide margin.

The role of side effects

Both medicines work on the gut, so side effects overlap. Nausea, diarrhoea, and vomiting are common early on, usually improving with gradual dose increases. Some people tolerate one drug better than the other, and this makes a difference in real life. While tirzepatide’s extra receptor action may boost results, it can also mean a stronger risk of gastrointestinal upset for certain users. Doctors often stress that the “better” medicine is the one you can actually stay on.

Who can get them?

Access matters as much as trial data. In England, NICE has recommended Wegovy for adults with a BMI above 35 who have at least one weight-related condition, or in some cases with a BMI above 30. Mounjaro is still newer in the UK pathway: in 2025 NICE recommended it for type 2 diabetes, with weight-loss approvals under active review. This means that for now, Wegovy is more widely available in NHS weight-management services, while Mounjaro may be prescribed more often for people with diabetes.

Cost and commissioning

Another layer is cost. The NHS agrees confidential pricing with manufacturers, so the list price isn’t what services actually pay. For private patients, advertised prices for Mounjaro have shifted in recent months, sometimes higher than Wegovy. This variation means that even if tirzepatide appears more powerful on average, it isn’t always the most accessible option.

What matters beyond the numbers

Headlines often focus on percentages lost in trials, but people respond differently. Some may do brilliantly on Wegovy, others find Mounjaro a better fit, and others struggle with side effects on either. Weight management is rarely about one number; it’s about whether the treatment can be continued safely and whether it fits the person’s health priorities, such as improving blood sugar, lowering heart risk, or easing sleep apnoea.

Why context is key

Doctors will look at the bigger picture: Do you have type 2 diabetes? Is heart health the main concern? Have you tried other approaches before? Both drugs can reduce cardiovascular risk and improve metabolic markers, but long-term outcome data are still building for tirzepatide. Semaglutide already has strong evidence from the SELECT trial, which showed reduced heart attacks and strokes in people with overweight or obesity.

The bigger picture

So, is Mounjaro “better” than Wegovy? On average weight loss figures, tirzepatide may have the edge. But better does not mean best for every individual. Wegovy is currently more widely available through the NHS, has proven cardiovascular benefits, and may be easier to access. Mounjaro is a strong emerging option, especially for those with type 2 diabetes, and early data are encouraging. The right choice depends on personal health needs, side-effect tolerance, and access through NHS or private care.