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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Is Mounjaro Expensive in the UK?
Mounjaro (tirzepatide) is available in the UK through both NHS specialist services and private prescribing, with costs varying significantly depending on your route of access. Whether it's expensive depends on how you access it and your individual circumstances. Understanding both NHS and private pricing, plus how Mounjaro compares to alternatives like Wegovy, helps you make an informed decision about weight management options available to you.
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Calculate Your BMI Instantly
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 Costs: NHS vs Private Access in the UK
NHS Access: If prescribed through a specialist tier 3 weight management service, Mounjaro is typically provided free at point of use, though NHS availability varies significantly by region (integrated care board). Many areas have long waiting lists, and some regions have limited access due to budget constraints.
Private Access: Through a GPhC-registered online pharmacy following a clinical assessment, Mounjaro costs approximately £129–£320 per month depending on your dose. The KwikPen device contains 4 weeks of weekly injections. Prices vary between providers, and some offer subscription discounts.
- Starting dose (2.5 mg): typically £129–£180/month
- Mid-range dose (10 mg): typically £220–£280/month
- Maximum dose (15 mg): typically £280–£320/month
Dose increases usually occur every 4 weeks, so your costs may change as you titrate upwards.
Clinically BackedWeight Loss
No appointments. No waiting rooms. Just care — from a UK-regulated online pharmacy.
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: Cost and Effectiveness Comparison
Mounjaro (tirzepatide): Dual GIP+GLP-1 mechanism. Clinical trials (SURMOUNT) showed average weight loss of 15–21% depending on dose. Private cost: £129–£320/month. Available as once-weekly KwikPen.
Wegovy (semaglutide): GLP-1 only mechanism. Clinical trials (STEP) showed average weight loss of approximately 15%. Private cost: typically £120–£280/month depending on dose. Also once-weekly injection.
Individual results vary significantly. The choice between them depends on prescriber recommendation, your clinical assessment, cost, and personal preference. Try our free GLP-1 weight loss calculator above to see projected weight loss at different doses for either medication. Both require a prescription and clinical assessment to determine suitability.
- 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.
Why does Mounjaro cost different amounts between providers?
Prices vary between private GPhC-registered pharmacies based on their sourcing costs, operational overheads, and business models. Some offer loyalty discounts or subscription savings. Always compare providers, but ensure they require a proper clinical assessment from a UK-licensed prescriber—not just an online questionnaire.
Is Mounjaro cheaper on the NHS than private?
Yes—if you can access it through NHS specialist services, it's free at point of use. However, NHS availability is very limited and varies by region. Waiting lists can be many months. Private access is faster but costs £129–£320/month depending on dose.
Which is cheaper: Mounjaro or Wegovy?
Cost is very similar—both typically range £120–£320/month depending on dose and provider. Mounjaro's maximum dose (15 mg) may cost slightly more than Wegovy's maximum (2.4 mg). The difference is usually small; clinical suitability and prescriber recommendation are more important factors than cost alone.
Do I have to pay for Mounjaro privately if the NHS won't prescribe it?
Not necessarily. You can access Mounjaro privately through an online clinical assessment with a UK-licensed prescriber without waiting for or being turned down by NHS services. Private access is faster but comes with a cost. Eligibility criteria are similar to NHS (BMI ≥30 or ≥27 with comorbidities), though the prescriber makes the final decision.
Will the cost of Mounjaro go down in the UK?
Possibly over time as newer medications compete and patent protections change. For now, prices remain relatively stable. Checking different private providers regularly may reveal better deals. Some pharmacies offer price-matching or subscription discounts. Always verify the provider is GPhC-registered and requires a proper 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.