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
NHS Mounjaro Criteria and UK Eligibility
If you're wondering whether you might qualify for Mounjaro (tirzepatide) through the NHS, eligibility depends on your BMI, weight-related health conditions, and access to specialist tier 3 weight management services. NHS criteria are strict and vary by region. This guide explains who qualifies, how the assessment process works, and what to expect when seeking NHS Mounjaro treatment in the UK.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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 Eligibility Criteria for Mounjaro
NHS Mounjaro eligibility in the UK is based on NICE guidance and is assessed through specialist tier 3 weight management services. You may be eligible if you meet one of these criteria:
- BMI of 30 kg/m² or above (obesity), or
- BMI of 27–29.9 kg/m² (overweight) with at least one weight-related health condition
Weight-related conditions that may qualify include type 2 diabetes, prediabetes, high blood pressure, abnormal blood fats, obstructive sleep apnoea, or history of cardiovascular disease. For adults of South Asian, Chinese, Black African, or Black Caribbean backgrounds, the NHS recommends lower BMI thresholds — eligibility may begin at BMI 27.5 or above, because these groups face higher health risks at lower weights. You can use our free BMI calculator to check your current BMI instantly. Mounjaro is only prescribed through NHS specialist services, not by standard GPs, and availability varies significantly by region and ICB (Integrated Care Board).
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.
NHS Access vs Private Mounjaro Routes
Getting tirzepatide on the NHS requires referral to a specialist tier 3 weight management service, usually from your GP. However, NHS Mounjaro access is extremely limited in many regions, and waiting lists can be very long — sometimes 12–18 months or more. Private prescribing offers faster access through UK-licensed online prescribers following a clinical assessment, but costs approximately £150–£320 per month depending on dose. The NHS route is free but slow; the private route is quicker but paid. Some people use the private route while waiting for NHS assessment. Either way, Mounjaro is always a prescription-only medicine requiring clinical assessment, and it's used alongside a reduced-calorie diet and increased physical activity for best results.
- 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 do I know if I qualify for Mounjaro on the NHS?
Check your BMI using our BMI calculator. If your BMI is 30 or above, or 27–29.9 with a weight-related health condition, you may qualify. Lower thresholds apply if you're of South Asian, Black African, Black Caribbean, or Chinese heritage. Your GP can refer you to a specialist tier 3 service for formal assessment.
What is a tier 3 weight management service?
Tier 3 is the NHS specialist weight management level. It offers multidisciplinary assessment including dietary advice, behavioural support, and where appropriate, prescription medication like Mounjaro. Access is by GP referral, and services vary by region. Not all tier 3 services prescribe Mounjaro yet.
How long do NHS Mounjaro waiting lists typically take?
NHS waiting times vary by region but can range from 6–18 months or longer depending on local demand and funding. Private prescribing is faster (days to weeks) but involves a cost. Contact your local ICB for a more accurate timeline for your area.
Is Mounjaro the same as the tirzepatide available privately?
Yes — Mounjaro is the brand name for tirzepatide, whether prescribed on the NHS or privately. The medication is identical. The difference is the route of access, cost, and waiting time.
Can my GP prescribe Mounjaro directly, or do I need specialist referral?
In the UK, Mounjaro is typically only prescribed through specialist tier 3 services, not by standard GPs. Your GP can refer you to tier 3 services, but the prescription must come from the specialist team. NICE guidance supports this approach to ensure appropriate monitoring and support.
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.