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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Wegovy vs Mounjaro Cost in the UK
Both Wegovy (semaglutide) and Mounjaro (tirzepatide) are available in the UK, but their costs differ significantly depending on whether you access them through the NHS or privately. Understanding the pricing, eligibility criteria, and what each route involves can help you make an informed decision about weight management options available to you. This guide covers NHS eligibility, private costs, and how the two medications compare in terms of value for weight loss support.
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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 Eligibility for Wegovy and Mounjaro
Both medications are available through the NHS, but access is limited and varies significantly by region. You must be referred to a tier 3 specialist weight management service by your GP — neither medication is prescribed in general practice.
NHS eligibility requires:
- BMI of 30 kg/m² or above, OR BMI of 27–29.9 kg/m² with weight-related health conditions (type 2 diabetes, prediabetes, hypertension, dyslipidaemia, obstructive sleep apnoea, or cardiovascular disease)
- For South Asian, Chinese, Black African, or Black Caribbean adults: lower thresholds may apply (BMI 27.5 or above)
- Referral and assessment by a specialist service
NICE has approved both tirzepatide (Mounjaro) and semaglutide (Wegovy) for NHS use within specialist services. However, waiting lists for tier 3 services are long — in many regions, delays exceed 6–12 months. Some areas have limited availability due to budget constraints. Your GP can advise on availability in your local integrated care board (ICB).
Clinically BackedWeight Loss
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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.
Private Costs and Access for Wegovy and Mounjaro
Private costs (via online prescribing and GPhC-registered pharmacies) typically range from £129–£320 per month depending on the dose and provider. Mounjaro (tirzepatide) is usually priced at the higher end due to its dual GIP/GLP-1 mechanism, whilst Wegovy (semaglutide) is often slightly less expensive. Dose affects cost — higher maintenance doses cost more. Private access does not require NHS referral, making it faster: prescription issued after online clinical assessment, typically within 24–48 hours. No waiting list. However, costs are not covered by the NHS, so treatment is entirely self-funded. Your GP can advise whether private treatment is appropriate for your health, though you don't need a GP referral to access private prescribing.
Use our free GLP-1 weight loss calculator to explore potential outcomes with different doses, which may help you weigh up the cost versus benefit of each option. Whilst results vary significantly between individuals, understanding projected weight loss ranges can inform your decision. Consider also using our free BMI calculator to confirm your eligibility against NHS criteria or to track your baseline before starting any treatment. Combining lifestyle changes — reduced-calorie diet and increased physical activity — with either medication will deliver better results than medication alone.
- 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 cheaper than Wegovy on the NHS?
There is no direct cost difference on the NHS — both are available free at point of use through specialist weight management services. However, NHS access is limited and varies by region. Waiting times and availability depend on your local integrated care board, not on medication cost. Private costs differ: Mounjaro is typically slightly more expensive (£200–£320/month) than Wegovy (£129–£250/month) depending on dose and provider.
How much does Wegovy cost privately in the UK?
Private Wegovy costs typically range from £129–£250 per month depending on the dose and prescribing provider. The starting dose (0.25 mg) is cheaper than the maximum dose (2.4 mg). Costs vary between providers — it's worth comparing quotes from different GPhC-registered online pharmacies. Individual clinical assessments are required; some providers charge a consultation fee (typically £10–£50), whilst others include it in the medication cost.
Can I get Mounjaro on the NHS?
Yes, NICE has approved tirzepatide (Mounjaro) for use within NHS specialist weight management services (tier 3). You must be referred by your GP and meet eligibility criteria (BMI ≥30, or ≥27 with weight-related health conditions). However, NHS availability is limited — many regions have significant waiting lists (6–12+ months). Ask your GP about tier 3 services in your area and current waiting times. Private access is available without NHS referral.
What's the difference between Mounjaro and Wegovy in terms of effectiveness?
Clinical trials show both are effective for weight loss. Mounjaro (tirzepatide) uses a dual GIP/GLP-1 mechanism and in SURMOUNT trials achieved average weight loss of 15–21% of body weight. Wegovy (semaglutide) is a GLP-1 agonist and in STEP trials achieved average weight loss of approximately 15% of body weight. Results vary significantly between individuals. Individual response depends on dose, adherence, lifestyle changes, and personal metabolism — not just the medication type.
How does dose titration affect the cost of Wegovy and Mounjaro?
Both medications require gradual dose titration (increasing the dose over weeks). This means initial costs are lower (starting doses are cheaper per injection). Mounjaro uses a slower titration (minimum 4 weeks per dose level) than Wegovy, so your spending increases gradually over several months. This can be an advantage if budgeting privately — you start with lower costs and increase only if you tolerate the medication well and wish to escalate to higher doses.
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.