AskAwayHealth
Mounjaro vs Wegovy UK: How to Choose the Best Weight Loss Injection
July 9, 2025
Let’s help you make the right choice: Mounjaro vs Wegovy? Given the increasing popularity in the UK of both, which is the best weight loss injection?
Well the answer is not so simple. Both drugs have advantages for different considerations. In this post we help you decide how to choose the option that will work best for you.
In plain terms:
- Mounjaro helps people lose slightly more weight (20-25% vs 14-17%)
- Wegovy is proven to protect your heart
- Both costs range from £140-£350/month privately
What’s Ahead
How These Injections Work
| Injection | How It Works | Effects | Best For |
| Wegovy (Semaglutide) | Mimics the GLP-1 hormone to suppress appetite and slow digestion. | Weight loss: 14-17% after 68 weeks Waist reduction: 13 cm | Wegovy works well for moderate goals. Faster initial loss (5% in 4 weeks) |
| Mounjaro (Tirzepatide) | Targets both GLP-1 and GIP hormones, reducing appetite while improving insulin sensitivity. | Weight loss: 20-25% after 72 weeks Waist reduction: 18cm | Mounjaro suits those needing >20% weight loss. Peak effect at 6 months |
Mounjaro vs Wegovy (UK) Side Effects Compared
Common Side Effects
Both cause GI issues (nausea, diarrhoea, constipation) due to slowed digestion. Mounjaro users report slightly higher burping/flatulence. They are also both associated with tiredness.
| Risk | Mounjaro | Wegovy |
| Pancreatitis (pancreas inflammation) | ✅ | ✅ |
| Gallbladder issues eg gallstones | ✅ | ✅ |
| Thyroid Cancer | ❌ | ✅ with a family history |
| Hypoglycaemia (low blood sugar) | ⚠️with insulin | ⚠️with insulin |
How to Choose: 5 Decision Factors
- Weight Loss Goals:
- Choose Mounjaro if you are aiming for >20% loss
- Choose Wegovy for 10-15% loss or faster initial results
- Health Profile:
- Wegovy is preferable if heart disease/diabetes exists (proven benefits)
- Mounjaro is recommended for insulin resistance or prediabetes
- Budget:
- Wegovy costs ~£50*/month less than Mounjaro privately(* variable rates and subject to clinic). Read for more cost details.
- Side Effect Tolerance:
- Mounjaro: Higher GI symptoms
- Wegovy: Requires thyroid monitoring
- Access Urgency:
- Wegovy has wider NHS availability today.
- Mounjaro access expands (NHS) in 2025, but available via private and online clinics
Tirzepatide vs Semaglutide
Yes, after a 5-6 week “washout period.” Transition should be handled under medical supervision
Wegovy (available since 2023); Mounjaro rollout starts 2025
Reputable clinics require BMI verification and checks for other health conditions, but not universal blood tests/ECGs
Yes, but disclose all medications – tirzepatide/semaglutide may alter drug absorption
These drugs may reduce the effectiveness of hormone medications like birth control pills. The recommendation is to switch to methods like the coil, implant or depot shot. Watch to learn more.
More Reading
Editing by AskAwayHealth Team
Disclaimer
All AskAwayHealth articles are written by practising Medical Practitioners on various healthcare conditions to promote quality healthcare.
The advice in our material is not meant to replace a qualified healthcare practitioner’s management of your specific condition.
Don’t hesitate to contact a health practitioner to discuss your condition or reach us directly here.
Image Credits: Canva
Review Date
For medical review by July 2027
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