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 Cost Comparison in the UK
Mounjaro (tirzepatide) costs vary significantly depending on whether you access it through the NHS or privately in the UK. Private costs range from approximately £129–£320 per month depending on dose, while NHS access is free but available only through specialist tier 3 weight management services with potential waiting lists. This guide explains the cost differences, access routes, and what to expect when seeking Mounjaro treatment in the UK.
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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.
Private Mounjaro Costs and Access in the UK
Private prescription Mounjaro (tirzepatide) in the UK is dispensed through GPhC-registered online pharmacies following an online clinical assessment with a UK-licensed prescriber. Costs typically range from £129–£320 per month depending on the dose prescribed. The starting dose (2.5 mg) is usually less expensive than higher maintenance doses, with the maximum 15 mg dose commanding the highest price per KwikPen. Each pen contains a 4-week supply of once-weekly injections. Private access does not require NHS referral and is often faster than NHS routes — most people receive a prescription within days of their online assessment. However, private treatment is an out-of-pocket cost not covered by NHS insurance. Cost comparison across providers is recommended, as prices vary between pharmacies even at the same dose level.
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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.
NHS Access vs Private Cost Routes
NHS access to Mounjaro is free but only through specialist tier 3 weight management services — not standard GP prescription. You require a GP referral to access NHS specialist services, which assess your BMI, health conditions, and suitability for treatment. However, availability varies significantly by region and ICB (Integrated Care Board), with waiting lists often running months to years in many areas. NICE has approved tirzepatide for use within NHS weight management services, but access depends on local capacity. The private route bypasses NHS waiting lists but involves immediate costs. Use our free GLP-1 weight loss calculator to project potential results with Mounjaro, then discuss cost and access options with your GP or a private 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.
How much does Mounjaro cost privately in the UK?
Private Mounjaro typically costs £129–£320 per month depending on dose and pharmacy. The starting 2.5 mg dose is usually cheaper than higher doses. Each KwikPen contains a 4-week supply. Costs vary between GPhC-registered pharmacies, so comparing providers is recommended before purchasing.
Is Mounjaro free on the NHS in the UK?
Yes, Mounjaro is free on the NHS if prescribed through a specialist tier 3 weight management service. However, you need a GP referral and must meet BMI and health criteria. Availability varies by region and waiting lists can be lengthy — sometimes months to years depending on your local ICB.
What's the difference between Mounjaro dose costs?
The starting 2.5 mg dose is generally the cheapest. Costs increase with higher doses, with the maximum 15 mg dose typically the most expensive per month. Prices also differ between pharmacies. Most people titrate (gradually increase) doses over weeks, so early-stage treatment costs less than maintenance doses.
How do I access Mounjaro privately in the UK?
Private access is through an online consultation with a UK-licensed prescriber. If approved, your prescription is dispensed by a GPhC-registered pharmacy. The process is typically faster than NHS referral — most people receive prescriptions within days. No NHS referral is required, but treatment costs are out-of-pocket.
Can I compare Mounjaro vs Wegovy costs?
Wegovy (semaglutide) pricing is similar to Mounjaro, ranging £129–£320 monthly depending on dose. Both are available privately through online prescribing. Mounjaro uses a dual GIP+GLP-1 mechanism while Wegovy is GLP-1 only. Compare both cost and mechanism with your prescriber to decide which suits you best.
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.