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
Free tracker included with every download this week
Can I Get Mounjaro For Free in the UK?
Mounjaro (tirzepatide) may be available for free through the NHS if you meet specific eligibility criteria and are referred to a specialist weight management service. However, NHS access is limited and varies significantly by region. Many people in the UK access Mounjaro through private prescription instead. This guide explains both pathways, eligibility requirements, and what to expect with each route.
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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 Access to Mounjaro — How It Works
NICE approved tirzepatide (Mounjaro) for NHS use in 2024 within specialist tier 3 and tier 4 weight management services. However, NHS access is not automatic — you must meet specific criteria and be referred by your GP to a specialist centre.
NHS eligibility criteria:
- BMI of 30 kg/m² or above, OR
- BMI of 27–29.9 kg/m² with at least one weight-related health condition (type 2 diabetes, hypertension, dyslipidaemia, sleep apnoea, or cardiovascular disease)
- For South Asian, Chinese, Black African, or Black Caribbean adults: lower BMI thresholds may apply (27.5 or above)
- Must have tried lifestyle interventions first
The key challenge: NHS specialist weight management services have limited capacity. Waiting times can be months or even years in many areas. Your GP must refer you, and the service must assess you as suitable. Even if eligible, you may not be offered treatment due to service availability or funding restrictions. Regional NHS Integrated Care Boards (ICBs) control budgets and access varies widely across England, Scotland, Wales, and Northern Ireland.
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.
Private Access — Faster Alternative
Private prescription pathways are more widely available and faster. Many people access Mounjaro through GPhC-registered online clinics following an online clinical assessment with a UK-licensed prescriber. This does not require an NHS referral and you can start within days, not months.
Private costs: approximately £150–£320 per month depending on your dose (starting at 2.5 mg, titrating to a maximum of 15 mg weekly). You pay privately; the NHS does not fund private prescriptions. You can also use our GLP-1 weight loss calculator to estimate potential weight loss at different doses of tirzepatide, which may help inform your decision alongside your prescriber's guidance. Always ensure the prescriber is UK-licensed and the pharmacy is GPhC-registered.
- 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.
Is Mounjaro free on the NHS?
Mounjaro may be free through the NHS if you meet eligibility criteria and are referred to a specialist weight management service. However, NHS availability is limited and varies by region. Many people find private prescription is faster and more accessible, though this involves payment.
How do I get Mounjaro on the NHS?
Ask your GP for a referral to your local tier 3 or tier 4 specialist weight management service. Your GP must assess you first. The specialist service will decide whether to prescribe Mounjaro based on NHS criteria and available funding. Waiting lists can be very long.
What is the difference between NHS and private Mounjaro?
The medication is identical. NHS access requires a GP referral and specialist assessment; private access is via online consultation with a prescriber. NHS is free but has waiting lists; private costs £150–£320/month but is faster to access.
Can I switch from private Mounjaro to NHS Mounjaro?
Yes, you can ask your GP to refer you to the NHS service once you are established on private treatment. However, the NHS service may not continue your prescription immediately — they assess you separately based on their criteria and funding.
What if my region doesn't offer Mounjaro on the NHS?
Regional variation is significant. If your local NHS service does not offer tirzepatide, you can ask your GP about referral to a neighbouring ICB service, or consider private prescription to access treatment faster while waiting for NHS availability.
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.