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 NHS Requirements in the UK
Mounjaro (tirzepatide) is available through the NHS for weight management, but eligibility depends on your BMI, health conditions, and which NHS region you live in. Access is typically through specialist tier 3 or tier 4 weight management services, not standard GP prescriptions. Understanding the NHS requirements can help you know whether you might qualify and how to request a referral from your GP.
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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
To qualify for Mounjaro through the NHS in the UK, you generally need to meet one of these criteria:
- BMI of 30 or above (obesity), OR
- BMI of 27–29.9 combined with at least one weight-related health condition (overweight with comorbidity)
For adults of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds apply: eligibility may start at BMI 27.5 or above. This accounts for higher cardiovascular and metabolic risk at lower BMI levels in these populations.
Weight-related health conditions that may qualify include type 2 diabetes or prediabetes, high blood pressure (hypertension), abnormal blood fats (dyslipidaemia), obstructive sleep apnoea, and a history of heart attack or stroke. Your GP will assess whether your circumstances meet NHS criteria during an initial consultation.
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 via the NHS
Access to Mounjaro through the NHS is not available directly from your GP surgery. Instead, you'll need a referral to a specialist weight management service — typically a tier 3 (community-based) or tier 4 (hospital-based) service. Your GP can refer you if they believe you meet the criteria and have not responded adequately to previous weight management interventions.
Waiting times for NHS specialist services vary significantly by region and can be several months or longer. Once referred, the specialist team will conduct a full health assessment, review your weight loss history, and decide whether Mounjaro is appropriate for you. If approved, you'll receive your Mounjaro prescription and injection training through the NHS service at no cost.
- 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's the main difference between NHS and private Mounjaro access in the UK?
NHS access requires referral to a specialist tier 3/4 weight management service, typically involves waiting lists, and is free once approved. Private access is through online consultations with UK-licensed prescribers, no NHS referral needed, faster processing, but costs apply (typically £129–£320+ monthly depending on dose).
Do I automatically qualify for NHS Mounjaro if my BMI is 30?
Not automatically. You must have a BMI of 30 or above, or 27–29.9 with weight-related health conditions like type 2 diabetes or hypertension. Your GP also assesses whether you've tried other weight management approaches first and whether the specialist service has capacity.
Can my GP prescribe Mounjaro directly without a specialist referral?
No. Mounjaro is only prescribed through NHS specialist weight management services (tier 3 or 4), not by GPs in standard primary care. Your GP can refer you, but the prescription comes from the specialist team after assessment.
What happens if I'm referred to an NHS weight management service but there's a long waiting list?
Some people choose private Mounjaro access via online prescribers while waiting for NHS services. This is a personal choice. If you're interested in either route, our free GLP-1 weight loss calculator can help you estimate potential outcomes at different doses.
Does ethnicity affect my NHS Mounjaro eligibility criteria?
Yes. If you're of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS recognises lower BMI thresholds due to higher metabolic risk. You may qualify at BMI 27.5 or above instead of 30, reflecting NICE guidance on ethnicity-adjusted thresholds. ```
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.