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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How to Apply for Mounjaro Through the NHS
Mounjaro (tirzepatide) is available through the NHS for eligible adults with obesity or overweight with weight-related health conditions. Unlike private prescribing, NHS access requires a referral to a specialist tier 3 weight management service in your area. This guide explains the eligibility criteria, referral process, and what to expect from NICE-approved NHS prescribing pathways. Availability varies by region, and waiting times can be significant in many areas.
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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 and the Referral Pathway
To access Mounjaro through the NHS, you must meet specific eligibility criteria and be referred to a specialist tier 3 weight management service. You are typically eligible if you have a BMI of 30 kg/m² or above, or a BMI of 27–29.9 with at least one weight-related health condition such as type 2 diabetes, prediabetes, high blood pressure, sleep apnoea, or cardiovascular disease.
For people of South Asian, Chinese, Black African, or Black Caribbean heritage, the NHS applies lower thresholds — eligibility may begin at BMI 27.5 or above, recognising higher health risks at lower weights.
- Step 1: Discuss weight management with your GP
- Step 2: Your GP assesses whether you meet eligibility criteria
- Step 3: If eligible, your GP refers you to your local tier 3 specialist weight management service
- Step 4: The specialist service conducts a full assessment before prescribing
NICE guidance (NG189) supports the use of tirzepatide for weight management within specialist services. However, NHS availability is patchy — some integrated care boards (ICBs) offer Mounjaro readily, whilst others have restrictions or long waiting lists.
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 Access to Mounjaro in the UK
NHS access is free at the point of use but requires a referral and specialist assessment through tier 3 services. Waiting times vary — some areas have waits of several months or longer. Private access is available through GPhC-registered online pharmacies without an NHS referral, following a clinical assessment with a UK-licensed prescriber. This route is faster but costs approximately £129–£320 per month depending on your dose.
Both routes require a prescription and clinical assessment. Use our free GLP-1 weight loss calculator to estimate potential weight loss with Mounjaro at different doses, and our BMI calculator to check your starting point. Your choice of route depends on your circumstances, timeline, and budget.
- 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 difference between NHS and private Mounjaro prescribing in the UK?
NHS access is free but requires a tier 3 referral and may involve waiting lists. Private access is faster (typically 1–2 weeks) but costs £129–£320 per month. Both require clinical assessment and a valid prescription.
How long does it take to get Mounjaro through the NHS?
Waiting times vary significantly by region (ICB). Some areas offer appointments within weeks; others have waiting lists of several months or longer. Contact your local weight management service for timescales.
Can my GP prescribe Mounjaro directly without a specialist referral?
In most areas, no. GPs typically refer eligible patients to specialist tier 3 weight management services, where Mounjaro is initiated and managed. Some pilot areas may differ — ask your GP about local arrangements.
What health conditions make me eligible for Mounjaro on the NHS?
Qualifying conditions include type 2 diabetes, prediabetes, high blood pressure, abnormal blood fats, sleep apnoea, and a history of heart attack or stroke. You need a BMI of 30+, or 27–29.9 with one of these conditions.
Is Mounjaro dose titration different on the NHS than privately?
No. Both NHS and private Mounjaro follows the same dosing schedule — starting at 2.5 mg and increasing by 2.5 mg every 4 weeks to a maximum of 15 mg. Your prescriber monitors progress and adjusts based on your response.
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.