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 UK NHS Criteria: Who Qualifies?
If you're considering Mounjaro in the UK, understanding NHS eligibility criteria is essential. Mounjaro (tirzepatide) is a prescription-only weight loss injection licensed for adults meeting specific BMI and health thresholds. This guide explains the exact criteria, how NHS access works, and whether you might be eligible. Eligibility varies by region and individual circumstances, so speaking with your GP is the first step to understanding your options.
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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
To access Mounjaro through the NHS in the UK, you must meet specific BMI thresholds or have weight-related health conditions. The primary criteria are:
- BMI of 30 or above (obesity), regardless of health conditions
- BMI of 27–29.9 (overweight) with at least one weight-related health condition
Weight-related conditions that may qualify include type 2 diabetes, prediabetes, high blood pressure, abnormal cholesterol, obstructive sleep apnoea, or a history of heart attack or stroke. For adults of South Asian, Chinese, Black African, or Black Caribbean backgrounds, lower BMI thresholds apply—eligibility may start at BMI 27.5 or above, as these groups face higher cardiovascular and metabolic risks at lower BMI levels. Check your personal BMI using our free BMI calculator to see where you stand, then discuss these criteria with your GP to explore next steps.
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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 and Regional Variation
NHS access to Mounjaro in the UK operates through specialist tier 3 weight management services, not standard GP prescriptions. Your GP can refer you to a specialist service in your area, where a multidisciplinary team assesses your eligibility and manages your treatment. However, NHS availability varies significantly by region and local integrated care board (ICB) decisions. In many areas, waiting lists for tier 3 services can extend several months or longer. If you meet the criteria but face a long NHS wait, private prescription options are available through GPhC-registered online prescribers following a clinical assessment—though these involve a private cost. Our weight loss calculator can help you understand potential outcomes with prescription weight loss medication alongside lifestyle changes.
- 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.
Do I need to be obese to qualify for Mounjaro on the NHS?
No. You can qualify with a BMI of 27–29.9 (overweight) if you have a weight-related health condition like type 2 diabetes, high blood pressure, or sleep apnoea. However, a BMI of 30 or above (obesity) alone meets criteria without additional conditions.
What if I'm of South Asian or Black African heritage—do different criteria apply?
Yes. The NHS recognises that South Asian, Chinese, Black African, and Black Caribbean adults face higher metabolic risks at lower BMI levels. Lower thresholds apply—eligibility may begin at BMI 27.5 or above rather than 30. Discuss your ethnicity and health context with your GP.
How do I access Mounjaro through the NHS?
Start by speaking with your GP about weight management options. If you meet criteria, your GP can refer you to a specialist tier 3 weight management service. The specialist team assesses you further and determines whether Mounjaro is appropriate. This process can take weeks to months depending on local waiting lists.
What's the difference between NHS and private access to Mounjaro?
NHS access requires referral to specialist services and may involve waiting lists but costs nothing. Private access is faster—through online prescribers and GPhC-registered pharmacies—but involves a cost (typically £150–£300+ per month depending on dose). A licensed prescriber assesses you in both routes.
Can I get Mounjaro from my GP directly, or must I see a specialist?
In most cases, Mounjaro is prescribed through specialist tier 3 services, not standard GP practices. Your GP initiates the referral, but the specialist team manages the prescription and ongoing monitoring. Some areas may have different pathways—your GP can advise on your local arrangements.
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.