The UK's most complete GLP-1 guide
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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 UK Pricing vs Wegovy — What You Need to Know
If you're considering prescription weight loss treatment in the UK, understanding the cost difference between Mounjaro and Wegovy is important. Both are licensed GLP-1 receptor agonist injections available through NHS specialist services or private prescribing, but they work differently and cost differently. This guide compares Mounjaro pricing with Wegovy to help you understand your options and what to expect when speaking with your GP or a licensed prescriber about which might be suitable for your individual circumstances.
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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) and Wegovy (semaglutide) are both prescription-only weight loss injections available in the UK, but they have different costs and work in different ways. Mounjaro is typically priced between £180–£320 per month depending on dose, whilst Wegovy costs around £129–£300 per month depending on dose. The difference partly reflects their mechanisms: Mounjaro is a dual GIP and GLP-1 receptor agonist, activating two hormone pathways, whilst Wegovy is a GLP-1 agonist only. In clinical trials (SURMOUNT for Mounjaro, STEP for Wegovy), Mounjaro showed average weight loss of approximately 15–21% of body weight at maximum dose, whilst Wegovy showed approximately 15% at 2.4mg. These are clinical trial averages — individual results vary significantly. Costs also vary between private providers, and NHS access through specialist services is free (though waiting lists can be substantial in many regions).
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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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Which Is Right for You? Individual Assessment and NHS Access
Whether Mounjaro or Wegovy is suitable depends on your individual health, medical history, and prescriber assessment — not just cost. Both require a clinical assessment to confirm eligibility. On the NHS, both are available through tier 3 specialist weight management services, though regional availability and waiting times vary. For private prescriptions, you'll need an online consultation with a UK-licensed prescriber; eligibility is based on BMI and weight-related health conditions. Our GLP-1 weight loss calculator can help you estimate potential outcomes at different doses. Use our BMI calculator to check where you stand relative to NHS eligibility thresholds. Your prescriber will discuss which medication suits your circumstances, considering factors like your medical history, other medications, and personal preference.
- 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.
How much does Mounjaro cost privately in the UK?
Mounjaro typically costs £180–£320 per month depending on dose (2.5mg to 15mg). Costs vary between private providers. The KwikPen contains 4 weeks of doses. Exact pricing should be confirmed with your chosen prescriber, as fees differ.
Is Wegovy cheaper than Mounjaro in the UK?
Wegovy is often slightly cheaper, ranging from approximately £129–£300 per month depending on dose. However, pricing varies between providers. The cost difference may not be substantial enough to be the deciding factor — individual suitability matters more.
Can I get Mounjaro or Wegovy free on the NHS?
Yes, both are available free through NHS specialist tier 3 weight management services if you meet eligibility criteria (BMI ≥30, or ≥27 with weight-related health conditions). However, waiting lists for NHS specialist services can be very long in many regions.
What's the difference between Mounjaro and Wegovy mechanisms?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist, activating two hormone pathways. Wegovy (semaglutide) is a GLP-1 agonist only. The dual mechanism may contribute to different weight loss outcomes, though individual results vary considerably.
Which injection will make me lose more weight — Mounjaro or Wegovy?
Clinical trial data shows Mounjaro achieved slightly higher average weight loss (15–21%) than Wegovy (approximately 15%), but individual results vary significantly. Suitability depends on your health, not predicted weight loss. Your prescriber will advise which is appropriate for you.
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.