Dr David Porter

Medications such as Mounjaro (tirzepatide), Ozempic (semaglutide) and Wegovy (semaglutide) are reshaping the way we think about obesity management. Once reserved for type 2 diabetes, these treatments are now recommended under strict clinical guidelines to support weight loss and reduce health risks.

But as demand has soared, private sector prices have risen sharply, raising important questions about access, equity and long-term sustainability.

The evidence

Both semaglutide and tirzepatide are part of a class of drugs called GLP-1 receptor agonists (tirzepatide also targets GIP receptors). They work by reducing appetite, slowing gastric emptying, and improving blood sugar control.

• In the STEP programme, patients taking semaglutide (Wegovy) lost an average of 15% of body weight over 68 weeks, alongside lifestyle interventions.
• In the SURMOUNT-1 trial, tirzepatide (Mounjaro) achieved weight loss of up to 21% of body weight.

These results are unmatched by lifestyle change alone and have been shown to improve cardiovascular risk factors such as blood pressure, cholesterol and glucose regulation.

The price of progress

As clinical success stories have grown, so too has demand. Shortages and supply constraints have driven significant private price increases, leading some patients to switch from Mounjaro to Wegovy on cost grounds rather than medical suitability.

This trend underscores two issues:

• Affordability: Higher prices risk creating a divide in access between those who can and cannot afford private prescriptions.

   

• Prioritisation: With limited supply, these medicines must be reserved for patients who meet clinical criteria, rather than for casual or cosmetic use.

Access in the UK

On the NHS, semaglutide (Wegovy) can be prescribed for adults with obesity (BMI ≥35 plus weight-related conditions, or BMI 30–34.9 under specialist referral). For higher-risk ethnic groups, eligibility may begin at BMI 27.5. Treatment is time-limited to two years and must be delivered alongside lifestyle and behavioural support.

Mounjaro is licensed in the UK for type 2 diabetes, with its use for obesity under active NICE review.

The Opus approach

Our Body Optimisation service takes a comprehensive, evidence-led approach to health and performance. Where indicated, GLP-1 medications such as Wegovy or Mounjaro may form part of an individualised programme. Crucially, these medicines are never used in isolation, they are prescribed only after thorough medical assessment, and always as part of a plan that includes nutrition, physical activity and ongoing clinical supervision.

This ensures safety, maximises results, and supports long-term change well beyond the treatment period.

The clinical evidence for Mounjaro, Ozempic and Wegovy is strong. In carefully selected patients, these medications can deliver substantial and sustained weight loss, reduce cardiovascular risk factors, and improve overall health outcomes in ways that lifestyle changes alone often cannot achieve. Large-scale trials consistently demonstrate their effectiveness, with results showing average weight reductions of 15–21% when used under medical supervision alongside diet and activity interventions.

However, the recent rise in private costs highlights a growing challenge. These treatments are powerful tools, but they must remain accessible to those who meet the clinical criteria and stand to benefit most. Prescribing must always be guided by thorough assessment, safety monitoring, and integration into a holistic plan that prioritises long-term health rather than short-term results.

As demand continues to increase, the focus must remain on responsible, evidence-based use, ensuring that patients receive safe, regulated care and that these medicines are recognised not as shortcuts, but as part of a broader medical approach to managing obesity and its associated risks.