Wegovy vs Mounjaro: How Do They Compare for Weight Loss?

Wegovy (semaglutide) and Mounjaro (tirzepatide) are two of the most widely discussed weight loss medications currently available. Both work by targeting the biological systems that regulate appetite, but they do so in slightly different ways.

If you are considering treatment, understanding the differences between these medications can help you make a more informed decision. For a broader overview of how weight loss medications work, see our guide How Weight Loss Medications Work: A Medical Overview.

How Wegovy and Mounjaro work
Wegovy works by mimicking the GLP-1 hormone, which helps regulate appetite, increase feelings of fullness, and slow stomach emptying.

Mounjaro works on both GLP-1 and GIP receptors. This dual mechanism may enhance appetite regulation and metabolic effects for some individuals.

If you would like a deeper explanation of these pathways, see our article What Are GLP-1 Medications and Why Do They Help With Weight Loss.

Effectiveness and weight loss results
Both medications have been shown to support meaningful weight loss in clinical trials. On average, studies suggest that tirzepatide may lead to greater weight loss in some individuals, although results vary.

It is important to recognise that individual response differs. Factors such as lifestyle, consistency, and overall health all influence outcomes.

Side effects and tolerability
Both Wegovy and Mounjaro have similar side effect profiles, with the most common symptoms affecting the digestive system. These include nausea, vomiting, diarrhoea, constipation, and reduced appetite.

For more detailed guidance, see our articles Wegovy Side Effects: What’s Common, What’s Rare, and What to Expect and Mounjaro Side Effects and Tolerability: A Balanced View.

Which medication is better
There is no single answer to which medication is better. The most appropriate option depends on individual factors, including medical history, treatment goals, tolerability, and clinician recommendation.

Some people may respond better to Wegovy, while others may find Mounjaro more effective or better tolerated.

Suitability and prescribing considerations
Both medications require a clinical assessment before starting treatment. This ensures that the medication is safe and appropriate for your individual circumstances.

For more information, see our guide Who Is Suitable for Weight Loss Medication.

Access and availability in the UK
Wegovy and Mounjaro may be available through specialist NHS services or private providers. Availability, cost, and prescribing criteria can vary.

It is important to choose a regulated provider that offers proper assessment and ongoing support.

Emerging alternatives
New medications such as retatrutide are being studied and may offer additional options in the future. However, these treatments are not yet approved for routine use in the UK.

Making an informed decision
Choosing between Wegovy and Mounjaro should be based on a balanced understanding of benefits, risks, and personal circumstances.

For a complete overview of how medication fits into long term weight management, see our pillar guide Weight Loss Medication in the UK: A Patient-Centred Pillar Guide.

Further reading
• NICE guidance on obesity management
• NHS weight management services
• Clinical research on semaglutide and tirzepatide