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 Qualifies for Mounjaro on the NHS?
Getting Mounjaro (tirzepatide) through the NHS in the UK involves meeting specific eligibility criteria and accessing specialist weight management services. The NHS has strict thresholds based on your BMI and existing health conditions. Understanding these criteria helps you know whether referral to a tier 3 specialist service might be appropriate for you. Your GP can discuss your individual circumstances and whether you meet the requirements for this prescription-only injection. This guide explains the official NHS criteria and how the assessment process works.
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.
Official NHS Eligibility Criteria for Mounjaro
The NHS may consider tirzepatide (Mounjaro) for adults who meet one of these criteria:
- BMI of 30 or above (obesity category) — regardless of other health conditions
- BMI of 27–29.9 (overweight) plus at least one weight-related health condition
For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS applies lower BMI thresholds: eligibility may start at BMI 27.5 or above, because these groups have higher cardiovascular and metabolic risk at lower BMI levels. Weight-related health conditions that may qualify include type 2 diabetes, prediabetes, high blood pressure, abnormal cholesterol levels, obstructive sleep apnoea, and previous heart attack or stroke. Use our free BMI calculator above to check where you fall, and discuss your results with your GP. Mounjaro is prescription-only and requires a clinical assessment — your prescriber will evaluate your full health picture, not just your BMI.
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.
How to Access Mounjaro Through the NHS
NHS access to Mounjaro happens through tier 3 specialist weight management services, not through standard GP prescriptions. You'll need a referral from your GP to your local integrated care board's (ICB) specialist service. However, NHS availability varies significantly by region — some areas have very limited services and substantial waiting lists that can extend months or years. Your GP can tell you what's available in your area and whether you're eligible to be referred. If NHS waiting times are too long, you may explore private prescribing through a UK-licensed online service, which doesn't require NHS referral but involves costs. Either route requires a clinical assessment confirming you meet eligibility criteria for this injection.
- 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?
Adults with a BMI of 30 or above qualify regardless of health conditions. Those with a BMI of 27–29.9 may qualify if they have weight-related conditions like type 2 diabetes or high blood pressure. South Asian, Chinese, Black African, and Black Caribbean adults may qualify at lower thresholds (from 27.5 BMI) due to higher health risks at lower weights.
Do I need to be referred by my GP to get Mounjaro on the NHS?
Yes, you'll need a referral from your GP to your local tier 3 specialist weight management service. Your GP can discuss your eligibility and arrange the referral if appropriate. However, NHS availability and waiting times vary significantly by region.
What health conditions make me eligible for NHS Mounjaro?
Weight-related health conditions that may support eligibility include type 2 diabetes, prediabetes, high blood pressure (hypertension), abnormal blood fat levels (dyslipidaemia), obstructive sleep apnoea, and previous heart attack, stroke, or cardiovascular disease. Your GP will assess your individual circumstances.
How long are NHS waiting lists for Mounjaro?
Waiting times vary significantly by region and NHS service availability. Some areas have waiting lists of several months to over a year. Contact your local NHS service directly for current waiting times, or ask your GP for information about your specific area's tier 3 weight management service.
Can I get Mounjaro privately if I don't qualify for the NHS or prefer not to wait?
Yes, Mounjaro is available through private prescribing via UK-licensed online services. This doesn't require NHS referral but involves costs and requires an online clinical assessment. You'll need a prescription from a UK-licensed prescriber and dispensing through a GPhC-registered pharmacy.
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.