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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Who is Eligible for Mounjaro on the NHS in the UK?
Mounjaro (tirzepatide) is a prescription-only weight loss injection now available through NHS specialist weight management services in the UK. However, not everyone who wants it will qualify — eligibility depends on your BMI, age, health conditions, and whether you've tried other weight management approaches first. This guide explains who can access Mounjaro through the NHS and what the assessment process involves. Use our free BMI calculator above to check where you currently sit on the NHS weight categories.
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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 Eligibility Criteria for Mounjaro in the UK
In the UK, Mounjaro may be prescribed by NHS specialist tier 3 and tier 4 weight management services if you meet these criteria:
- BMI of 30 or above (obesity), or
- BMI of 27–29.9 (overweight) with at least one weight-related health condition
- Age 18 or over — Mounjaro is not approved for under 18s
- Tried lifestyle changes first — diet and exercise support without sustained weight loss
Weight-related health conditions that may qualify you include type 2 diabetes, prediabetes, high blood pressure, abnormal cholesterol, obstructive sleep apnoea, and a history of cardiovascular disease. For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS applies lower BMI thresholds — eligibility may begin at BMI 27.5 or above because these groups face higher metabolic health risks at lower weights. You cannot access Mounjaro on the NHS if you are pregnant, breastfeeding, or have had a severe allergic reaction to tirzepatide. NICE (National Institute for Health and Care Excellence) has approved tirzepatide for NHS use within specialist weight management services, though regional availability varies significantly across different NHS integrated care boards.
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 vs Private Routes for Mounjaro in the UK
There are two ways to access Mounjaro in the UK. NHS access requires a GP referral to your local tier 3 specialist weight management service, but waiting lists can be months or even years in many areas — availability depends entirely on your region. Assessment through the NHS is free, but the process is lengthy and involves multiple appointments. Private access is faster — you can obtain a prescription from a UK-licensed prescriber through an online consultation without an NHS referral, and it's dispensed by a GPhC-registered pharmacy. Private prescriptions typically cost £129–£320 per month depending on your dose and provider. For most people, private access is quicker, while NHS access is free but involves significant waiting times. Whichever route you choose, you'll receive the same medication and will need to follow the same dose titration schedule, starting at 2.5 mg and increasing weekly over 20 weeks to your target dose. Try our GLP-1 weight loss calculator to explore potential outcomes at different doses.
- 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.
Can I get Mounjaro on the NHS if my BMI is 27?
If your BMI is 27–29.9, you may qualify for NHS Mounjaro if you have at least one weight-related health condition such as type 2 diabetes, prediabetes, high blood pressure, or sleep apnoea. For South Asian, Chinese, Black African, or Black Caribbean adults, lower thresholds apply — eligibility can begin at BMI 27.5. Your GP can assess whether you meet the criteria for referral to specialist services.
How long is the NHS waiting list for Mounjaro?
NHS waiting times for specialist weight management services vary significantly by region. Some areas have waiting lists of 6–12 months, while others may take longer. Private access is typically faster — you can receive a prescription within days through an online assessment. Check with your local integrated care board for specific waiting times in your area.
What happens if I don't meet NHS eligibility criteria but want Mounjaro?
If you don't qualify for NHS Mounjaro, you can explore private prescribing through a UK-licensed prescriber. Private providers assess your individual circumstances and may offer prescriptions to those who fall outside strict NHS criteria. Private treatment costs roughly £129–£320 monthly but is available without NHS referral or waiting lists.
Do I need to try other weight loss methods before accessing Mounjaro?
Yes, the NHS typically expects evidence of previous weight management attempts (diet, exercise, behaviour change support) before referring you to specialist services for prescription medication. Private prescribers may have different assessment criteria. Your prescriber will review your personal health history to determine suitability.
Is Mounjaro the same as Ozempic or Wegovy?
No — Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist, while Wegovy (semaglutide) is a GLP-1 agonist only. Ozempic is semaglutide approved for diabetes, not weight loss. All three are prescription-only, but Mounjaro and Wegovy are specifically licensed for weight management in the UK. Your prescriber will assess which is most suitable for you.
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.