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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Mounjaro And Wegovy Costs In The UK — What's The Price Difference?
Mounjaro (tirzepatide) and Wegovy (semaglutide) are both prescription-only weight management injections available in the UK, but their costs differ significantly depending on whether you access them through the NHS or privately. Understanding the price difference can help you make an informed decision about which option suits your situation. Both medications may support weight loss when used alongside a reduced-calorie diet and increased physical activity, though individual results vary.
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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.
NHS Access And Private Pricing For Both Medications
NHS access: Both Mounjaro and Wegovy may be available through NHS specialist tier 3 weight management services, but availability varies dramatically by region (ICB). NHS prescriptions have no direct cost to you, though waiting lists in many areas can extend several months. Private prescribing is faster — after an online clinical assessment with a UK-licensed prescriber, costs typically range from £129 to £320 per month, depending on the dose and provider.
- Mounjaro (tirzepatide): Private pricing usually £180–£320/month for doses up to 15mg weekly
- Wegovy (semaglutide): Private pricing typically £129–£249/month for doses up to 2.4mg weekly
- Both require repeat prescriptions, so ongoing costs accumulate
The final price depends on your starting dose, how quickly you escalate, and your chosen pharmacy. Use our GLP-1 weight loss calculator to explore projected results at different doses, which may help inform your cost-benefit 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.
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Why The Price Difference Exists And Key Considerations
Mounjaro and Wegovy differ in mechanism and dosing schedules, which affects manufacturing and pricing. Mounjaro is a dual GIP and GLP-1 receptor agonist with a maximum dose of 15mg, while Wegovy is a GLP-1-only agonist with a maximum dose of 2.4mg — this means Mounjaro typically requires higher injection volumes and different manufacturing processes. Clinical trials showed Mounjaro helped participants lose approximately 20.9% body weight at maximum dose, compared to Wegovy's approximately 14.9%, though individual results vary significantly.
Both medications require a prescription from a UK-licensed prescriber following a clinical assessment. Your GP can refer you to NHS services, or you can pursue private prescribing. Many people find private access faster when NHS waiting lists are lengthy in their area.
- 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 more expensive than Wegovy in the UK?
Generally yes. Private Mounjaro costs typically £180–£320/month depending on dose, while Wegovy usually ranges £129–£249/month. However, both are free through the NHS if prescribed by a specialist tier 3 service, though NHS availability varies significantly by region and waiting lists can be lengthy.
Can I get Mounjaro or Wegovy on the NHS?
Both may be available through NHS specialist weight management services (tier 3), but access depends on your regional ICB and local commissioning decisions. You'll typically need a GP referral. Many areas have long waiting lists. Private prescribing offers faster access if you can afford it.
What's the monthly cost of each dose for Mounjaro and Wegovy privately?
Mounjaro ranges approximately £180–£320/month for starting doses (2.5mg) through maximum (15mg). Wegovy typically costs £129–£249/month from starting dose (0.25mg) to maximum (2.4mg). Exact pricing varies by pharmacy — always get a quote before committing.
Is there a significant weight loss difference between Mounjaro and Wegovy that justifies the price difference?
Clinical trials showed Mounjaro produced average weight loss of approximately 20.9% body weight, while Wegovy showed approximately 14.9%. However, individual results vary significantly. Your prescriber can help assess whether the potential additional loss justifies the higher cost for your situation.
Do I need to pay for repeat prescriptions if I get these on the NHS?
No — once prescribed by an NHS specialist service, there is no patient cost for NHS-prescribed medications. Private prescriptions, however, require payment each time you repeat, so ongoing costs accumulate over months and years of treatment.
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.