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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Can You Get Mounjaro Free on the NHS?
Mounjaro (tirzepatide) is now approved for NHS use in the UK, but accessing it free through the NHS requires meeting specific eligibility criteria and being referred to specialist weight management services. This guide explains NHS access, NICE guidance, tier 3 services, and how Mounjaro compares to other UK weight loss options. Use our free BMI calculator above to check your starting point, then explore what NHS support may be available to you.
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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 and Access in the UK
NICE approved Mounjaro (tirzepatide) for NHS use in 2023, but availability varies significantly across UK regions. NHS access requires referral to a tier 3 specialist weight management service — you cannot obtain it directly from your GP. Eligibility typically requires:
- BMI of 30 kg/m² or above, or BMI 27–29.9 with weight-related health conditions (type 2 diabetes, hypertension, cardiovascular disease, sleep apnoea)
- For South Asian, Chinese, Black African, or Black Caribbean adults: lower thresholds may apply (BMI 27.5+)
- Documented attempts at weight loss through lifestyle changes
- No medical contraindications
The NHS tirzepatide KwikPen starts at 2.5 mg, escalating to a maximum of 15 mg weekly. Access through tier 3 services often involves waiting lists of 6–18 months in many areas, though this varies by region (ICB). Your GP must refer you; you cannot refer yourself directly to specialist services.
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 Mounjaro Access in the UK
Two routes exist for obtaining Mounjaro in the UK:
- NHS: Free at point of use following specialist assessment, but limited availability and long waiting times. Regional variation is significant — some areas have active services, others have waiting lists exceeding 18 months.
- Private: Available through GPhC-registered online clinics following an online clinical assessment, typically costing £129–£320 per month depending on dose. No waiting lists, faster access, but not free.
Many patients choose private access due to NHS waiting times. Calculate your potential weight loss using our GLP-1 weight loss calculator to understand projected outcomes at different doses, which may help inform your decision. Your GP can advise whether you meet NHS criteria and discuss both routes available to you.
- 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 NICE guidance on Mounjaro (tirzepatide) for the NHS?
NICE approved tirzepatide for NHS use in adults with obesity or overweight with comorbidities in 2023. It's recommended as part of tier 3 specialist weight management services, alongside lifestyle changes. Access is means-tested and region-dependent; availability varies significantly across UK ICBs.
How long are NHS waiting lists for Mounjaro in the UK?
NHS waiting times for specialist weight management services vary by region. Many areas have waiting lists of 6–18 months or longer. Some regions have shorter waits; a few have minimal services. Contact your local ICB weight management service for current waiting times in your area.
What's the difference between NHS and private Mounjaro access?
NHS Mounjaro is free but involves specialist referral, waiting lists, and regional availability. Private access is available within 1–2 weeks through online clinics but costs £129–£320 monthly. Both require clinical assessment; both use the same medication and KwikPen delivery system.
Can I get Mounjaro free if I don't meet NHS BMI criteria?
No. NHS Mounjaro requires BMI ≥30, or BMI 27–29.9 with weight-related comorbidities. Lower thresholds apply for certain ethnic groups. If you don't meet criteria, private access may be available following an online assessment, though it's not free.
How do I get referred to an NHS tier 3 weight management service?
Ask your GP about tier 3 weight management referral in your area. Your GP will assess your eligibility and refer you if appropriate. Some areas have rapid-access pathways; others have longer waits. Not all GP practices refer regularly, so discuss explicitly with your surgery.
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.