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
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How Much Is Mounjaro UK Per Month?
Mounjaro (tirzepatide) costs vary in the UK depending on whether you access it through the NHS or privately. On the NHS, Mounjaro is free once prescribed through specialist weight management services, though access is limited and waiting lists can be lengthy. Privately, Mounjaro costs approximately £129–£320 per month depending on your dose and provider. This page breaks down UK pricing, compares Mounjaro to Wegovy, explains dose titration, and helps you understand what to expect when accessing weight loss injection treatment in the UK.
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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 UK Cost: NHS vs Private Pricing
NHS access: Mounjaro is free on the NHS when prescribed through tier 3 specialist weight management services, but access is limited by region and waiting lists. Referral from your GP is required, and many areas have extended waiting periods.
Private cost: Private Mounjaro prescriptions in the UK typically cost:
- 2.5–5 mg dose: approximately £129–£180/month
- 7.5–10 mg dose: approximately £180–£240/month
- 12.5–15 mg dose: approximately £240–£320/month
Prices vary between providers and include the KwikPen device. A mounjaro kwikpen contains 4 weeks' supply (4 injections). Costs may also include the clinical assessment fee (typically £20–£50 with private prescribers). Compare this with our GLP-1 weight loss calculator to estimate potential outcomes at different doses.
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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.
Mounjaro vs Wegovy: Side-by-Side Cost and Mechanism Comparison
Both Mounjaro and Wegovy are prescription weight loss injections licensed in the UK, but they differ in mechanism and cost. Wegovy (semaglutide) costs similarly—approximately £129–£300/month privately—but uses a single GLP-1 mechanism, whereas Mounjaro is a dual GIP+GLP-1 agonist. Clinical trials show both can support meaningful weight loss: SURMOUNT (Mounjaro) reported average loss of 15–21% body weight; STEP (Wegovy) showed approximately 15% loss. Your suitability depends on individual health factors. A prescriber will assess which medication—if either—is appropriate following a clinical assessment. Use our BMI calculator to check your starting point and discuss medication eligibility with your GP or a licensed prescriber.
- 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?
Yes, Mounjaro (tirzepatide) is available on the NHS through specialist tier 3 weight management services. However, access is limited by region and waiting lists can be very long. You'll need a GP referral. Many people choose private prescriptions for faster access.
What's the difference between Mounjaro and Wegovy?
Mounjaro is a dual GIP+GLP-1 agonist; Wegovy is a GLP-1 agonist only. Both support weight loss when combined with diet and activity changes. Costs are similar (£129–£320/month privately). Choice depends on prescriber assessment and individual suitability—neither is "better" universally.
How much does a Mounjaro KwikPen cost in the UK?
A Mounjaro KwikPen (4-week supply, 4 injections) costs £129–£320 depending on dose strength. Exact pricing varies by private provider. NHS prescriptions are free but may involve long waiting lists.
Can I get Mounjaro prescription weight loss without a GP referral?
Yes. You can access Mounjaro privately through a licensed online prescriber without an NHS referral. You'll need a clinical assessment, and prescription is issued if appropriate. Private access is faster but not free.
What dose of Mounjaro should I start on?
Mounjaro starts at 2.5 mg weekly for the first 4 weeks. Doses increase gradually (5 mg, 7.5 mg, 10 mg, 12.5 mg, 15 mg maximum) based on tolerance and prescriber guidance. Your dose titration schedule will be set by your prescriber following clinical assessment.
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.