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- How GLP-1 medications work
- Mounjaro vs Wegovy compared
- Injection instructions
- Side effects & solutions
- What to eat on treatment
- FAQs answered
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Mounjaro and Wegovy Prices in the UK
If you're comparing weight management options, understanding the cost and pricing of Mounjaro and Wegovy is an important part of the decision. Both are prescription-only GLP-1 or dual-action medications available in the UK, but they differ in dosing schedules, mechanism, and price. This guide breaks down current pricing, what affects cost, and how to access both medications through NHS specialist services or private prescribers following a clinical assessment.
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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.
How Mounjaro and Wegovy Differ in Cost and Mechanism
Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist — it activates two hormone pathways — while Wegovy (semaglutide) is a single GLP-1 receptor agonist. This mechanism difference is reflected in their dosing and, typically, pricing.
Mounjaro pricing in the UK through private prescribing typically ranges from £129–£320 per month depending on dose. The KwikPen contains 4 weekly injections, so monthly cost varies by dose tier (2.5 mg to 15 mg). Wegovy pricing ranges from approximately £150–£300 per month for the pre-filled pen at maintenance dose (2.4 mg). Both require a prescription from a UK-licensed prescriber and a clinical assessment to determine suitability.
- Mounjaro: once-weekly injection, doses from 2.5 mg to 15 mg maximum
- Wegovy: once-weekly injection, doses from 0.25 mg to 2.4 mg maximum
- Both: prescription-only, require clinical assessment, available through private online prescribing or NHS specialist services
Try our GLP-1 weight loss calculator above to explore projected outcomes with different medications.
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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.
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Clinical Evidence and Individual Suitability
The SURMOUNT-1 trial showed Mounjaro achieved average weight loss of approximately 20.9% body weight at the 15 mg dose. The STEP-1 trial showed Wegovy achieved approximately clinically studied weight loss at the 2.4 mg dose. However, individual results vary significantly — these are clinical trial averages, not assured outcomes.
Your eligibility and suitability for either medication depends on your personal health, BMI, any weight-related health conditions, and medical history. Use our free BMI calculator to check your current BMI and see which category you fall into. A licensed prescriber will assess whether Mounjaro, Wegovy, or another approach is most appropriate for you following a clinical consultation.
- 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.
What's the main difference between Mounjaro and Wegovy?
Mounjaro (tirzepatide) is a dual GIP+GLP-1 receptor agonist activating two hormone pathways. Wegovy (semaglutide) is a GLP-1 agonist only. Both are once-weekly injections, but Mounjaro typically reaches higher doses (15 mg max) and showed slightly higher average weight loss in clinical trials, though individual results vary.
Are Mounjaro and Wegovy available on the NHS in the UK?
Both are licensed for NHS use in the UK through specialist tier 3 weight management services. Access requires referral from your GP and assessment by a specialist team. Availability and waiting times vary significantly by region. Both are also available through private online prescribing following a clinical assessment.
Why do Mounjaro and Wegovy prices differ?
Pricing reflects the different mechanisms, maximum doses, and supply costs. Mounjaro pricing depends on the dose tier (2.5–15 mg per week). Wegovy pricing is typically higher at maximum dose (2.4 mg) due to dosing requirements. Private prescribing costs vary by provider and dose. Always compare current pricing with your chosen pharmacy.
Can I switch from Wegovy to Mounjaro or vice versa?
Switching between medications is possible but must be managed by your prescriber. The doses are not directly equivalent — approximate conversions exist (e.g., Wegovy 2.4 mg ≈ Mounjaro 15 mg) but any switch requires professional guidance. Never switch doses or medications without consulting your prescriber.
Which medication will help me lose more weight — Mounjaro or Wegovy?
Clinical trial data suggests Mounjaro may achieve slightly higher average weight loss, but individual outcomes vary considerably. Suitability depends on your health, medical history, and how you respond to treatment. Your prescriber will recommend the most appropriate medication for your specific circumstances, not based solely on weight loss potential.
Ready to take control of your weight loss journey?
Start with a free BMI check, explore your GLP-1 options, or begin tracking your progress today. No sign-up. No cost. Just results.