Compare Mounjaro vs Wegovy vs Saxenda
Side-by-side comparison of the UK's three leading weight loss injection medications. All data from peer-reviewed clinical trials.
Weight Loss Medication Comparison Table
All clinical data sourced from the landmark trials for each medication. Prices reflect current UK private pharmacy rates as of February 2026.
| Feature | Mounjaro | Wegovy | Saxenda |
|---|---|---|---|
| Active Ingredient | Tirzepatide | Semaglutide | Liraglutide |
| Manufacturer | Eli Lilly | Novo Nordisk | Novo Nordisk |
| Mechanism | Dual GIP + GLP-1 | GLP-1 only | GLP-1 only |
| Injection Frequency | Once weekly | Once weekly | Once daily |
| Average Weight Loss | 22.5% (15mg)¹ | 14.9% (2.4mg)² | 8.0% (3mg)³ |
| Trial Duration | 72 weeks | 68 weeks | 56 weeks |
| Starting Price (UK) | From £149/month | From £155/month | From £155/month |
| Dose Range | 2.5–15mg | 0.25–2.4mg | 0.6–3.0mg |
| Escalation Period | ~20 weeks | ~16 weeks | ~5 weeks |
| NICE Approved | Yes (TA924) | Yes (TA875) | Yes (TA664) |
| NHS Available | Limited | Limited | Limited |
| Pancreatitis Risk | Small risk⁴ | Small risk⁴ | Small risk⁴ |
Key Differences
Mounjaro — Most Effective
With an average weight loss of 22.5% in clinical trials, Mounjaro is the most effective option currently available. Its dual GIP/GLP-1 mechanism sets it apart from Wegovy and Saxenda, which target only the GLP-1 receptor.¹
Wegovy — Proven Track Record
Wegovy was the first GLP-1 to gain NICE approval for weight management and has extensive real-world evidence. At 14.9% average weight loss, it sits between Mounjaro and Saxenda in terms of effectiveness.²
Saxenda — Fastest Escalation
Saxenda reaches its full dose in just 5 weeks (vs 16–20 for Wegovy/Mounjaro), but requires daily injections rather than weekly. At 8.0% average weight loss, it is less effective but may suit patients who cannot tolerate the newer medications.³
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Important Medical Information
This website provides general information about weight loss medications for educational purposes only. It is not intended as medical advice, diagnosis, or treatment. Always consult your GP or qualified healthcare professional before starting any weight loss medication. Individual results may vary.
WhichWeightMeds.org is an independent comparison platform and is not affiliated with any pharmacy, manufacturer, or healthcare provider. We do not prescribe, sell, or dispense medications.
Sources & References
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