Mounjaro is one of several weight loss treatments available in the UK, each with different costs, effectiveness profiles, and suitability criteria. Understanding how they compare helps you and your prescriber choose the best option for your circumstances and budget.
Mounjaro (Tirzepatide)
- Monthly cost: £150-260 (depending on dose)
- Administration: Weekly subcutaneous injection
- Average weight loss: 15-22% of body weight in clinical trials
- Mechanism: Dual GIP/GLP-1 receptor agonist
- Annual cost: £1,800-3,120
Wegovy (Semaglutide 2.4 mg)
- Monthly cost: £150-250 (depending on dose and availability)
- Administration: Weekly subcutaneous injection
- Average weight loss: 12-15% of body weight in clinical trials
- Mechanism: GLP-1 receptor agonist
- Annual cost: £1,800-3,000
Wegovy is similarly priced to Mounjaro but clinical trial data suggests Mounjaro may produce greater average weight loss due to its dual receptor mechanism. However, individual responses vary and some patients do better on semaglutide.
Orlistat (Xenical/Alli)
- Monthly cost: £18-45 (prescription Xenical) or £30-50 (over-the-counter Alli)
- Administration: Oral capsule taken with meals
- Average weight loss: 3-5% of body weight
- Mechanism: Lipase inhibitor (blocks fat absorption)
- Annual cost: £216-600
Orlistat is significantly cheaper but produces much more modest weight loss. It also carries unpleasant gastrointestinal side effects related to fat malabsorption. It may suit patients with a smaller amount of weight to lose or those who cannot afford injectable treatments.
Mysimba (Naltrexone/Bupropion)
- Monthly cost: £70-100
- Administration: Oral tablets (twice daily)
- Average weight loss: 5-8% of body weight
- Mechanism: Combination of opioid antagonist and antidepressant affecting appetite centres
- Annual cost: £840-1,200
Mysimba sits between Orlistat and the injectables in both cost and effectiveness. It may be particularly suitable for patients whose overeating is driven by emotional or reward-based eating patterns.
Bariatric Surgery
- Cost: £4,000-15,000 privately (free on NHS if eligible)
- Average weight loss: 20-35% of body weight
- One-time cost but with ongoing dietary supplement needs
Surgery produces the greatest weight loss but carries surgical risks and requires lifelong dietary modifications. It is typically reserved for patients with a BMI of 40+ or 35+ with significant comorbidities.
Cost-Effectiveness Considerations
When comparing costs, consider the cost per percentage of body weight lost:
- Mounjaro: Approximately £120-175 per 1% body weight lost
- Wegovy: Approximately £140-215 per 1% body weight lost
- Orlistat: Approximately £55-150 per 1% body weight lost
- Mysimba: Approximately £120-185 per 1% body weight lost
On a pure cost-per-result basis, Mounjaro and Orlistat both offer reasonable value, though through very different levels of effectiveness. Discuss these options with your prescriber to find the best balance of cost, effectiveness, and suitability for your individual situation.