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 Criteria for NHS Prescribing in the UK
Mounjaro (tirzepatide) is now approved for prescription through NHS specialist weight management services in the UK, but eligibility depends on specific BMI thresholds and health conditions. Understanding the NHS criteria for Mounjaro can help you determine whether you might qualify for treatment through the NHS or explore private options. This guide outlines the official NHS eligibility requirements, how the prescription pathway works, and what to expect when accessing this medication 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.
NHS Mounjaro Eligibility Criteria and Requirements
NICE has approved tirzepatide (Mounjaro) for use within NHS specialist weight management services. However, access is through tier 3 or tier 4 specialist services, not standard GP prescription. You may be eligible for NHS Mounjaro if you meet one of these criteria:
- BMI of 30 kg/m² or above (obesity)
- BMI of 27–29.9 kg/m² (overweight) with at least one weight-related health condition
Weight-related conditions that qualify include type 2 diabetes or 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 heritage, lower BMI thresholds may apply — eligibility can begin at BMI 27.5 or above due to higher health risks at lower weights. Use our free BMI calculator above to check your personal BMI instantly. Mounjaro is available as a KwikPen injection, dosed from 2.5 mg up to 15 mg weekly, with dose adjustments based on individual response and tolerance.
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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 Access in the UK
NHS access to Mounjaro is limited to specialist tier 3 weight management services following referral from your GP. Waiting lists vary significantly by region (Integrated Care Board), and availability is not assured everywhere. NHS prescribing is free once approved. Private access is available through GPhC-registered online prescribing services following an online clinical assessment with a UK-licensed prescriber — no NHS referral needed. Private costs typically range from £129–£320 per month depending on dose. Both routes require a clinical assessment to confirm Mounjaro is appropriate for your health profile. Your GP can discuss which route may be more suitable for your circumstances.
- 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.
What is the exact BMI threshold for NHS Mounjaro in the UK?
The standard NHS threshold is BMI 30 kg/m² or above, or BMI 27–29.9 with a weight-related health condition. For people of South Asian, Chinese, Black African, or Black Caribbean heritage, lower thresholds may apply (BMI 27.5 and above). Your GP or specialist can assess your individual eligibility.
How do I access Mounjaro through the NHS?
You need referral from your GP to a tier 3 specialist weight management service in your area. These services provide comprehensive assessment, prescription, and support. Waiting times vary significantly by region. Private prescribing is an alternative if NHS waiting lists are long.
Does the NHS pay for Mounjaro if I'm eligible?
Yes, Mounjaro is free on the NHS if prescribed through an approved specialist weight management service and you meet the eligibility criteria. You will not pay for the medication itself, though you may pay standard prescription charges (currently £9.90 per item in England) unless you're exempt.
What conditions qualify for NHS Mounjaro eligibility?
Weight-related conditions include type 2 diabetes, prediabetes, high blood pressure, abnormal blood fats (dyslipidaemia), obstructive sleep apnoea, and history of heart attack or cardiovascular disease. Your GP will assess whether you have qualifying conditions.
Can I switch from private Mounjaro to NHS prescription?
Potentially yes, but this depends on your NHS region and specialist service availability. If you're already taking Mounjaro privately and later access NHS services, discuss continuity with your specialist. NHS services may have their own assessment processes and protocols to follow.
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.