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
Free tracker included with every download this week
How Much Does Mounjaro Cost in the UK?
Mounjaro (tirzepatide) is a prescription-only weight loss injection available in the UK through both NHS specialist services and private prescribing routes. The cost varies significantly depending on which route you choose. NHS access is free at point of use but involves referral and waiting lists, whilst private costs typically range from £129–£200+ per month depending on your dose. Understanding your options helps you find the most affordable and accessible route for your circumstances.
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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.
NHS Access and Costs for Mounjaro in the UK
Mounjaro through the NHS is free once prescribed, but access is limited and varies significantly by region. You'll need to be referred to a tier 3 specialist weight management service by your GP, and these services are not available in all areas.
- NHS eligibility requires a BMI of 30 or above, or 27–29.9 with weight-related health conditions (type 2 diabetes, hypertension, cardiovascular disease, sleep apnoea)
- For South Asian, Chinese, Black African, or Black Caribbean adults, thresholds may be lower (BMI 27.5+)
- Waiting lists for NHS specialist weight management services can be several months to over a year in many areas
- Once approved, Mounjaro is dispensed free through the NHS
- Your GP can discuss whether referral is appropriate for you and check local availability
Use our free BMI calculator above to check whether you meet the BMI threshold for NHS consideration.
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.
Private Prescribing and Cost-Effective Options
Private prescribing offers faster access without waiting lists. Costs depend on your dose — starting doses (2.5 mg) are typically £129–£150 per month, whilst maintenance doses (15 mg) cost £180–£220+ monthly. Each KwikPen contains 4 weekly doses.
- Access through GPhC-registered online prescribers following an online clinical assessment
- No NHS referral needed — available immediately if clinically suitable
- Costs vary between providers — compare options to find competitive pricing
- Some private providers offer loyalty discounts or bulk purchase options
To estimate your potential weight loss at different doses, try our free GLP-1 weight loss calculator on this page — it shows projected outcomes based on clinical trial data.
- 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 on the NHS or privately in the UK?
Mounjaro is free through the NHS but access is limited and involves waiting lists (often several months). Private prescribing costs £129–£220+ per month depending on dose, but offers immediate access without referral. For those who can access NHS specialist services quickly, NHS is significantly cheaper long-term.
How much does a single Mounjaro injection cost privately in the UK?
A single Mounjaro KwikPen (containing 4 weekly doses) costs approximately £129–£220 privately, depending on the dose strength and provider. This works out to roughly £32–£55 per weekly injection. Starting doses (2.5 mg) are cheaper than maintenance doses (15 mg).
Can I get Mounjaro prescribed by my GP on the NHS?
Mounjaro is not routinely prescribed by GPs on the NHS. You need referral to a tier 3 specialist weight management service. Your GP can discuss whether referral is appropriate and check whether such services are available in your area — availability varies significantly by region.
What is the cheapest way to access Mounjaro in the UK?
The cheapest way is through NHS specialist services (free), but this requires GP referral and waiting. If you can't wait or specialist services aren't available locally, private prescribing from GPhC-registered providers is the fastest option. Compare private providers to find competitive pricing for your dose.
How do I know if I'm eligible for Mounjaro on the NHS?
You're eligible if you have a BMI of 30+, or 27–29.9 with weight-related conditions like type 2 diabetes, hypertension, or cardiovascular disease. Lower thresholds apply to South Asian, Chinese, Black African, and Black Caribbean adults. Your GP can assess your eligibility and arrange referral to specialist services if appropriate.
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.