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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Monjaro on the NHS — How to Access Tirzepatide in the UK
Monjaro (tirzepatide) is now approved for use within NHS specialist weight management services in the UK, following NICE approval. However, NHS access is different from private access and depends on your local area, eligibility, and referral to tier 3 or tier 4 specialist services. This guide explains how the NHS pathway works, who qualifies, what to expect, and how Monjaro compares to accessing it privately. If you're considering Monjaro as a weight loss option, understanding both routes will help you make an informed decision about your weight management journey.
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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 Monjaro: Eligibility and Referral Pathway
NICE (National Institute for Health and Care Excellence) approved tirzepatide (Monjaro) for weight management within NHS tier 3 specialist services in 2023. However, NHS availability varies significantly across England, Scotland, Wales, and Northern Ireland — your local Integrated Care Board (ICB) decides whether and how to fund it.
To access Monjaro via the NHS:
- Your GP must refer you to a tier 3 or tier 4 specialist weight management service in your local area
- You must meet strict eligibility criteria: BMI ≥30 kg/m² (or ≥27.5 for South Asian/Black African/Caribbean/Chinese adults) with obesity-related health conditions, or BMI ≥35
- A specialist clinician will assess you and decide if Monjaro is appropriate
- The specialist service will prescribe, manage, and monitor your treatment
Waiting lists for NHS specialist weight management services can be very long in many areas — often 6 months to 2+ years depending on your region. During this time, your GP can support you with lifestyle interventions and other available treatments.
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 vs NHS Access — Key Differences
The main difference is speed and convenience. NHS access is free but involves GP referral, specialist assessment, and potentially long waiting lists. Private access is available through GPhC-registered online pharmacies following an online clinical assessment — faster (often within days) but costs £150–£320+ per month depending on dose.
Both routes require a prescription from a licensed UK prescriber. Both require you to demonstrate eligibility (BMI threshold and health conditions). The clinical decision about suitability is the same — the main difference is how quickly you can access it and whether you pay. Try our GLP-1 weight loss calculator to see projected outcomes, and use the BMI calculator to check your current BMI against NHS eligibility thresholds.
- 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 Monjaro free on the NHS?
Yes, Monjaro is free on the NHS if prescribed through a specialist tier 3 or tier 4 weight management service and your local ICB funds it. However, availability varies by region, and waiting lists can be very long. Private prescriptions cost £150–£320+ per month depending on your dose.
What is the NHS eligibility criteria for Monjaro?
Adults with BMI ≥30 kg/m² with weight-related health conditions (type 2 diabetes, hypertension, dyslipidaemia, sleep apnoea, cardiovascular disease), or BMI ≥35. For South Asian, Black African, Black Caribbean, and Chinese adults, lower thresholds apply (BMI ≥27.5). Your GP assesses this at referral.
How long does it take to get Monjaro on the NHS?
Waiting times for NHS specialist weight management services vary widely — typically 6 months to 2+ years depending on your region and service demand. This is why some people choose private access for faster availability, though at personal cost.
Can my GP prescribe Monjaro directly, or do I need a specialist?
Monjaro is prescribed through tier 3 or tier 4 specialist weight management services, not routinely by GPs. Your GP refers you to the specialist service, who then decides if Monjaro is appropriate and manages your treatment throughout.
What is the difference between NHS tirzepatide and private tirzepatide?
The medication is identical — tirzepatide 2.5 mg to 15 mg once weekly. The difference is funding (free vs paid), access speed (slow vs fast), and where you're managed (specialist clinic vs private prescriber + your own GP). Clinical outcomes are the same.
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.