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 for Diabetes in the UK — NHS Guidance
Mounjaro (tirzepatide) is a prescription-only injection licensed in the UK for both type 2 diabetes and weight management. Originally developed for diabetes control, Mounjaro works as a dual GIP and GLP-1 receptor agonist, helping regulate blood sugar levels and appetite. This NHS guide covers UK prescribing context, NICE approval status, eligibility criteria, and how to access Mounjaro through the NHS or private routes. Individual responses vary, and a GP clinical assessment is always required before prescription.
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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 Prescribing Status and Eligibility in the UK
NICE approval: NICE has approved tirzepatide (Mounjaro) for use within NHS specialist services for both type 2 diabetes and weight management. However, NHS prescribing varies significantly by region and depends on your local Integrated Care Board (ICB) commissioning decisions.
Type 2 diabetes eligibility: For diabetes management, Mounjaro is typically considered when other diabetes medications have not achieved adequate blood sugar control. You will usually need to have tried other treatments first, including metformin and other diabetes drugs.
Weight management eligibility (via NHS): If you have type 2 diabetes or prediabetes alongside overweight or obesity (BMI ≥27.5 for South Asian adults; ≥30 for other groups), you may be eligible for Mounjaro through an NHS tier 3 specialist weight management service. However, waiting lists are often months-long. Access pathways vary considerably across England, Scotland, Wales, and Northern Ireland.
- Requires GP referral to specialist service
- NHS availability depends on local commissioning
- Private prescribing available without waiting for NHS appointment
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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
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NHS vs Private Routes — How to Access Mounjaro in the UK
NHS route: Your GP can refer you to an NHS tier 3 weight management or diabetes specialist service. After clinical assessment, a consultant may prescribe Mounjaro if appropriate. This is free on the NHS, but waiting lists vary from weeks to years depending on your region and local demand.
Private route: UK-licensed prescribers can assess you via online consultation. If clinically appropriate, a prescription is issued and dispensed by a GPhC-registered pharmacy. This is available without waiting for NHS referral and typically costs £129–£250+ per month depending on dose. Try our free GLP-1 weight loss calculator to explore potential outcomes at different doses, and use our BMI calculator to assess your current health status.
- 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.
Can I get Mounjaro free on the NHS for type 2 diabetes?
Yes, NICE has approved tirzepatide for NHS use in type 2 diabetes and weight management. However, availability varies by region. Your GP can refer you to a specialist diabetes or weight management service, where a consultant will assess whether Mounjaro is appropriate for your individual situation. Waiting times can be significant.
What is the difference between Mounjaro and Ozempic for diabetes?
Both are GLP-1-based medicines, but Mounjaro is a dual GIP and GLP-1 agonist, while Ozempic (semaglutide) is a GLP-1 agonist only. Clinical trials suggest Mounjaro may produce slightly greater blood sugar control and weight loss. Both are prescription-only, but Mounjaro is specifically licensed for both diabetes and weight management in the UK.
How long does it take to get Mounjaro on the NHS?
This varies significantly by region and local ICB commissioning. Some areas offer appointments within weeks; others have waiting lists extending months or longer. Private prescribing typically offers faster access but involves a cost. Contact your GP or local specialist service for timelines specific to your area.
Can I use Mounjaro if I also have prediabetes?
Yes. If you have prediabetes alongside overweight or obesity, you may be eligible for Mounjaro through NHS specialist weight management services or via private prescribing. Your prescriber will assess your blood sugar levels, BMI, and overall health to determine suitability.
What is the tirzepatide dose range for type 2 diabetes?
Mounjaro starts at 2.5 mg weekly and can be titrated up to a maximum of 15 mg weekly. For diabetes, your specialist will determine the appropriate starting dose and escalation schedule based on your blood sugar control, tolerability of side effects, and individual health factors.
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.