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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Do I Qualify For Mounjaro On The NHS?
Mounjaro (tirzepatide) is available through the NHS for eligible adults, but access is limited to specialist tier 3 weight management services, not standard GP prescription. Eligibility depends on your BMI, any weight-related health conditions, and your local NHS availability. This guide explains the criteria and how to find out if you qualify. Use our free BMI calculator above to check your starting point, then assess your eligibility against the NHS thresholds outlined below.
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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 Eligibility Criteria For Mounjaro
The NHS approved tirzepatide (Mounjaro) through NICE guidance for use in specialist weight management services. You may be eligible if you meet one of these criteria:
- BMI of 30 or above (obesity), or
- BMI of 27–29.9 (overweight) with at least one weight-related health condition
Weight-related conditions include type 2 diabetes, prediabetes, high blood pressure, high cholesterol, obstructive sleep apnoea, or a history of heart disease or stroke. If you are of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds apply — you may be eligible from BMI 27.5 or above. Access is through NHS tier 3 services (specialist multidisciplinary weight management clinics), not your GP directly. You will typically need a referral from your GP and will undergo a clinical assessment to confirm suitability. Waiting lists for tier 3 services vary significantly by region and can be lengthy.
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
NHS route: Free at point of use if prescribed through a tier 3 service, but access is limited, waiting lists are long in many areas, and availability varies by region. Requires GP referral and specialist assessment. Not all NHS areas offer tirzepatide — some regions still rely on older medications like liraglutide (Saxenda).
Private route: Available through GPhC-registered online prescribing services without NHS referral. Costs range from approximately £150–£300 per month depending on dose. Faster access and wider availability, but requires out-of-pocket payment. Both routes require a clinical assessment by a UK-licensed prescriber. Our GLP-1 weight loss calculator can help you explore projected outcomes at different doses.
NHS Mounjaro prescribing is still evolving in the UK. NICE approved tirzepatide in 2023, but implementation across NHS trusts has been slow. Some specialist centres offer it; many do not yet. If you qualify but your local NHS doesn't offer Mounjaro, you may be offered semaglutide (Wegovy) instead, or directed to private options. Ask your GP or NHS weight management service what's currently available in your area. Eligibility assessment includes checking kidney and pancreas function, confirming no contraindications, and reviewing all your medications — especially diabetes treatments or oral contraceptives, which may need adjustment alongside Mounjaro therapy.
- 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 get referred to NHS tier 3 weight management services for Mounjaro?
Contact your GP and ask for a referral to your local NHS tier 3 (specialist) weight management service. Your GP will assess whether referral is appropriate, typically based on BMI and weight-related health conditions. Once referred, the specialist team will carry out a full assessment to determine if Mounjaro is suitable for you.
What if my NHS area doesn't offer Mounjaro yet?
Many NHS areas currently offer semaglutide (Wegovy) instead, or older medications like liraglutide. Ask your GP or the specialist service what weight loss medications are available locally. If Mounjaro isn't offered on the NHS in your area, you may consider private prescribing options through a UK-licensed prescriber.
Will I have to pay for Mounjaro if prescribed on the NHS?
No. If prescribed through the NHS, Mounjaro is provided free at point of use (you only pay standard prescription charges if applicable, or nothing if exempt). NHS prescriptions are subsidised. Private prescriptions cost significantly more — typically £150–£300 per month depending on dose.
How long are NHS waiting lists for tier 3 weight management services?
Waiting times vary widely by region and NHS trust. Some areas have waits of 6–12 months; others longer. Contact your local NHS weight management service directly for current waiting times. In the meantime, your GP can signpost you to tier 1 and tier 2 services (self-help tools and community programmes) that don't require waiting.
What's the difference between Mounjaro and Wegovy on the NHS?
Both are GLP-1-based weight loss injections approved by NICE for NHS use. Mounjaro (tirzepatide) is a dual GIP+GLP-1 agonist; Wegovy (semaglutide) is GLP-1 only. Clinical trials showed Mounjaro may produce slightly greater average weight loss, but Wegovy is more widely available on the NHS currently. Your prescriber will discuss which is 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.