The UK's most complete GLP-1 guide
Every Question Answered. Every Side Effect Explained.
- How GLP-1 medications work
- Mounjaro vs Wegovy compared
- Injection instructions
- Side effects & solutions
- What to eat on treatment
- FAQs answered
Free tracker included with every download this week
Is Mounjaro Going To Get Cheaper in the UK?
Mounjaro (tirzepatide) is currently one of the more expensive weight loss options available in the UK, but whether prices will fall depends on several factors including NHS rollout, generic availability, and market competition. Currently, private Mounjaro prescriptions cost between £200–£320 per month depending on dose, while NHS access through specialist services is free but involves significant waiting times. Understanding the pricing landscape and how it compares to alternatives like Wegovy can help you make an informed decision about your weight management options.
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Enter your height and weight below. Supports both imperial (stone & lbs) and metric (kg). Results include NHS category, healthy weight range, and ethnicity adjustments.
What Is BMI and Why Does It Matter?
Body Mass Index (BMI) is the most widely used screening tool for assessing whether your weight falls within a healthy range. Used by the NHS, GPs, and weight management services across the UK, BMI provides a quick snapshot of your weight relative to your height. The formula is simple: your weight in kilograms divided by your height in metres squared (kg/m²).
While BMI isn't a perfect measure — it doesn't account for muscle mass, bone density, or fat distribution — it remains the standard first step in identifying potential weight-related health risks including type 2 diabetes, cardiovascular disease, high blood pressure, and certain cancers.
The NHS also recommends adjusted thresholds for people of South Asian, Chinese, or Black African heritage — a BMI of 23 or above is classified as overweight, and 27.5 as obese. Our calculator includes this adjustment as a one-click toggle.
Mounjaro vs Wegovy: Current UK Pricing and Cost Comparison
Current private costs (as of 2026):
- Mounjaro (tirzepatide): approximately £200–£320 per month depending on dose
- Wegovy (semaglutide): approximately £129–£299 per month depending on dose
Both medications are prescription-only in the UK and require a clinical assessment before being prescribed. The exact cost varies by online prescriber, dose level, and whether you're stepping up through titration doses or already at maintenance. Mounjaro's dual GIP+GLP-1 mechanism differs from Wegovy's single GLP-1 mechanism, and clinical trial data shows Mounjaro achieved average weight loss of approximately 15–21% body weight across doses, whilst Wegovy achieved around 15% in trials. However, individual results vary significantly. Using our free GLP-1 weight loss calculator can help you estimate potential outcomes at different doses to guide your decision.
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How It Works
Three simple steps to understand your weight and take action.
Enter your height and weight in our free calculator. Get your BMI, NHS category, healthy weight range, and ethnicity-adjusted thresholds instantly.
If your BMI suggests you're overweight or obese, explore our GLP-1 calculators to project potential weight loss on Mounjaro or Wegovy.
Use our progress tracker to log your weight weekly, visualise your journey with charts, and stay motivated — all stored privately in your browser.
Free Weight Loss Tools & Guides
Everything you need to understand your weight, explore medication options, and track your progress — completely free.
Will Mounjaro Prices Fall? What Might Affect UK Costs
Several factors could influence Mounjaro pricing in the UK over time. NHS NICE approval in 2024 may eventually increase access through NHS specialist services, which would remove cost barriers for eligible patients but involves referral and waiting lists. Generic competition won't arrive until patent expiry (estimated 2031–2033), so branded Mounjaro will remain exclusive for several years. Market competition from other GLP-1 medications and future weight loss treatments may influence pricing. For now, NHS specialist services remain the most cost-effective route if you can access them, though waiting times in many regions are substantial. Private prescribing offers faster access without waiting lists. Your GP can discuss which route is appropriate for your individual circumstances and health needs.
- Dual GIP/GLP-1 receptor agonist
- Up to 22.5% body weight loss (SURMOUNT-1)
- Weekly injection, dose escalation over 20+ weeks
- Available via private prescription in the UK
- Doses: 2.5mg → 5mg → 7.5mg → 10mg → 12.5mg → 15mg
- GLP-1 receptor agonist
- Up to 15–17% body weight loss (STEP trials)
- Weekly injection, 5-step dose escalation
- NHS & private prescription available
- Doses: 0.25mg → 0.5mg → 1mg → 1.7mg → 2.4mg
Mounjaro vs Wegovy: Head-to-Head
A side-by-side comparison of the two most popular GLP-1 weight loss medications available in the UK.
| Feature | Mounjaro | Wegovy |
|---|---|---|
| Drug class | Dual GIP/GLP-1 agonist | GLP-1 agonist |
| Active ingredient | Tirzepatide | Semaglutide |
| Avg. weight loss | 15–22.5% | 12–17% |
| Key trial | SURMOUNT-1 (2022) | STEP 1 (2021) |
| Max dose | 15 mg weekly | 2.4 mg weekly |
| Escalation period | 20–32 weeks | 16–20 weeks |
| Administration | Weekly injection (pen) | Weekly injection (pen) |
| NHS availability | Private prescription only | NHS & private |
| Approx. private cost | £150–£250/month | £150–£300/month |
| Common side effects | Nausea, diarrhoea, constipation | Nausea, vomiting, diarrhoea |
Data sourced from SURMOUNT-1 and STEP 1 clinical trials. Costs are approximate and vary by provider. Always consult a prescriber.
Am I Eligible for Weight Loss Medication?
In the UK, eligibility for GLP-1 weight loss medications like Mounjaro and Wegovy is based on your BMI and overall health profile.
- BMI of 30 or above (obese)
- Age 18 or over
- No contraindicated conditions
- Committed to lifestyle changes
- BMI of 27 or above
- Plus type 2 diabetes
- Or high blood pressure
- Or obstructive sleep apnoea
Use our BMI calculator to check whether your BMI falls within the eligible range.
How We Built These Tools
Every calculator and guide on myweightcheck is built with accuracy and transparency in mind. Our BMI calculator uses the standard WHO formula with NHS-aligned category thresholds. Our GLP-1 projections are modelled on published clinical trial data from SURMOUNT and STEP studies.
All data stays on your device. We don't require sign-ups, and we don't store your health information on any server. Your progress tracker saves data locally in your browser using localStorage, so only you can see it.
We're based in the UK and our tools are designed specifically for UK users — supporting stone & lbs by default, referencing NHS guidelines, using NICE-approved medication data, and linking to GPhC-registered pharmacies.
Frequently Asked Questions
Common questions about BMI, weight loss medications, and our free UK tools.
Is Mounjaro available on the NHS in the UK?
Mounjaro is approved by NICE for NHS specialist tier 3 weight management services. However, availability varies significantly by region and waiting lists can be very long. Most people access Mounjaro privately through online prescribers, which costs £200–£320 per month depending on dose. Your GP can discuss NHS referral options if you meet eligibility criteria.
Why is Mounjaro more expensive than Wegovy?
Mounjaro typically costs more because it's a newer medication with a dual GIP+GLP-1 mechanism (vs Wegovy's single GLP-1 action), involves more complex titration schedules, and has less generic competition currently. Both require clinical assessment. Prices vary by prescriber and dose level. Use our GLP-1 weight loss calculator to compare projected outcomes at different costs.
Will Mounjaro get cheaper when generics arrive?
Yes, generic tirzepatide will likely be significantly cheaper once patents expire (estimated 2031–2033). However, branded Mounjaro will remain exclusive until then. In the meantime, NHS access through specialist services is free if you can access it, though waiting times vary widely by region.
What's the difference between Mounjaro and Wegovy in terms of results?
Clinical trials showed Mounjaro achieved 15–21% average body weight loss (depending on dose), whilst Wegovy achieved approximately 15%. However, individual results vary significantly based on lifestyle changes, adherence, and personal factors. Neither medication is assured to work at a specific level for any individual.
How do I access Mounjaro most affordably in the UK?
The most affordable route is through NHS specialist weight management services (free once referred), but waiting lists can be months or years in many areas. Private prescribing through online clinics costs £200–£320 per month. Your GP can advise on referral options. Calculate your BMI using our free tool to check eligibility criteria. ```
Ready to take control of your weight loss journey?
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