Complete Guide to Mounjaro (Tirzepatide) UK 2025

Published: 30 July 2025 | 15 min read

Table of Contents

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.

Key Facts:
  • 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
Serious Side Effects: Seek immediate medical attention for signs of pancreatitis (severe abdominal pain), allergic reactions, or severe dehydration.

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)
Use our price comparison tool to find the best current prices from UK pharmacies.

Where to Buy Mounjaro in the UK

Mounjaro is available through:

  1. Online pharmacies with consultation services
  2. Private weight-loss clinics
  3. 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

Currently, Mounjaro is primarily available privately. Some NHS weight management services may prescribe it in specific cases, but availability is very limited.

Mounjaro is designed for long-term use. Most people need to continue taking it to maintain weight-loss. Stopping typically results in weight regain.

Clinical trials suggest Mounjaro may produce greater weight-loss than Ozempic due to its dual hormone action. However, individual responses vary, and both are effective medications.
Medical Disclaimer

This guide is for informational purposes only. Always consult with a healthcare professional before starting any medication. Individual results may vary.

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