Complete Guide to Mounjaro (Tirzepatide) UK 2025
Published: 05 July 2025 | 15 min read
What is Mounjaro?
Mounjaro (tirzepatide) is a once-weekly injectable medication approved for treating type 2 diabetes and showing remarkable effectiveness for weight-loss. It's manufactured by Eli Lilly and became available in the UK in 2023.
- Active ingredient: Tirzepatide
- Administration: Weekly subcutaneous injection
- Prescription required: Yes
- Average weight-loss: 15-22% of body weight
How Does Mounjaro Work?
Mounjaro is unique because it's a dual GIP/GLP-1 receptor agonist, meaning it mimics two hormones:
- GLP-1 (Glucagon-like peptide-1): Slows gastric emptying and reduces appetite
- GIP (Glucose-dependent insulinotropic polypeptide): Enhances insulin secretion and may improve fat metabolism
This dual action makes Mounjaro potentially more effective than single-hormone medications like Wegovy or Ozempic.
Dosing Schedule
Mounjaro follows a gradual dose escalation to minimize side effects:
Week | Dose | Notes |
---|---|---|
Weeks 1-4 | 2.5mg | Starting dose |
Weeks 5-8 | 5mg | First increase |
Weeks 9-12 | 7.5mg | If tolerated |
Weeks 13-16 | 10mg | If additional control needed |
Week 17+ | 12.5mg or 15mg | Maximum doses |
Side Effects
Common side effects typically improve over time:
Common (>10% of users)
- Nausea
- Diarrhea
- Decreased appetite
- Constipation
- Vomiting
Less Common (1-10%)
- Abdominal pain
- Indigestion
- Fatigue
- Injection site reactions
- Dizziness
Expected Results
Clinical trials have shown impressive weight-loss results:
- SURMOUNT-1 Trial: Average 22.5% body weight-loss at highest dose (15mg)
- Timeline: Most weight-loss occurs in the first 6-9 months
- Maintenance: Continued use required to maintain weight-loss
Success Factors
- Combine with reduced calorie diet
- Regular physical activity
- Stay hydrated
- Follow dosing schedule carefully
Cost in the UK
Mounjaro prices vary significantly between pharmacies:
- Starting dose (2.5mg): £120-220 per month
- Maintenance doses: £170-350 per month
- Private prescription fee: £20-50 (one-time or monthly)
Where to Buy Mounjaro in the UK
Mounjaro is available through:
- Online pharmacies with consultation services
- Private weight-loss clinics
- Some NHS services (limited availability)
Always ensure you're buying from a registered UK pharmacy displaying the GPhC logo.
Mounjaro vs Wegovy
Feature | Mounjaro | Wegovy |
---|---|---|
Active ingredient | Tirzepatide | Semaglutide |
Mechanism | Dual GIP/GLP-1 | GLP-1 only |
Average weight-loss | 15-22% | 12-15% |
Injection frequency | Weekly | Weekly |
UK availability | Good | Limited |
Frequently Asked Questions
Medical Disclaimer
This guide is for informational purposes only. Always consult with a healthcare professional before starting any medication. Individual results may vary.