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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Is Mounjaro Available On The NHS?
Yes, Mounjaro (tirzepatide) is available on the NHS in the UK following NICE approval for weight management. However, availability is limited to specialist tier 3 and tier 4 weight management services, and you'll need referral from your GP. Access varies significantly by region, with some areas having long waiting lists. This guide explains NHS eligibility, how to access it, and what to expect in the application process.
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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 Eligibility And Access For Mounjaro
NICE approval: Mounjaro (tirzepatide) was approved by the National Institute for Health and Care Excellence (NICE) for weight management in UK adults. It is available through NHS specialist weight management services, but not as a standard GP prescription.
Who can access Mounjaro on NHS:
- Adults with a BMI of 30 kg/m² or above, or BMI of 27–29.9 with weight-related health conditions (type 2 diabetes, prediabetes, high blood pressure, abnormal cholesterol, sleep apnoea, or cardiovascular disease history)
- South Asian, Chinese, Black African, and Black Caribbean adults may qualify at lower BMI thresholds (typically 27.5 and above)
- Those who have tried lifestyle changes without sufficient weight loss
Access route: Your GP refers you to a specialist tier 3 weight management service in your local Integrated Care Board (ICB). The specialist team assesses you and decides whether Mounjaro is appropriate. This is different from private routes where you access a prescriber directly online.
Waiting lists for NHS specialist services vary greatly—some areas have waits of many months or longer.
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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
Everything you need to understand your weight, explore medication options, and track your progress — completely free.
NHS Vs Private Access To Mounjaro
NHS route advantages: Free medication once prescribed through NHS specialist services; ongoing medical support and monitoring; integrated care with your GP.
NHS route limitations: Often requires months-long waiting lists; availability varies by region; limited to specialist services (not standard GP prescribing); criteria can be stringent in some areas.
Private route: Available immediately without NHS referral; online clinical assessment with a UK-licensed prescriber; dispensed by GPhC-registered pharmacies; faster access but requires payment (typically £150–£320/month depending on dose).
Many people choose private access due to NHS waiting times. Whatever route you take, Mounjaro is a prescription-only medicine requiring clinical assessment and should be used alongside diet and activity changes.
- 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 for the NHS?
NICE (National Institute for Health and Care Excellence) recommends Mounjaro for weight management in eligible UK adults as part of NHS specialist weight management services. It is not recommended for routine prescribing in primary care (GP surgeries), only through tier 3 specialist services. NICE guidance recognises Mounjaro's clinical benefit but emphasises it should be part of a comprehensive weight management programme including diet and activity support.
How do I access Mounjaro through the NHS?
Ask your GP for a referral to your local specialist weight management service (tier 3). Your GP will complete a referral form. The specialist service will assess you over several weeks or months, considering your BMI, health conditions, and previous weight loss attempts. If Mounjaro is deemed appropriate, they will prescribe it and provide ongoing support. Waiting times vary by region—check with your local ICB (Integrated Care Board) for expected timescales.
What BMI do I need for NHS Mounjaro?
Generally, you need a BMI of 30 or above, or BMI of 27–29.9 with weight-related health conditions (type 2 diabetes, prediabetes, high blood pressure, high cholesterol, sleep apnoea, or cardiovascular disease). For South Asian, Chinese, Black African, or Black Caribbean individuals, the threshold may be lower (around 27.5 and above). Your GP or specialist will assess your individual circumstances. Use our free BMI calculator to check your starting point.
Why isn't Mounjaro available from my GP?
GPs cannot prescribe Mounjaro as a standard primary care medication. It is only available through specialist tier 3 weight management services because these services provide comprehensive support including dietary advice, physical activity programmes, and medical monitoring. This ensures safe, effective use as part of a broader weight management strategy rather than medication alone.
How does NHS Mounjaro compare to private access?
NHS access is free but involves waiting lists (sometimes many months); private access is immediate but costs £150–£320/month. Both require prescription and clinical assessment. NHS specialist services provide integrated support; private prescribers conduct online assessments. Many people choose private access due to NHS wait times, while others prefer NHS support and monitoring. Mounjaro works the same way regardless of access route—clinical trials showed average weight loss of 15–21% alongside diet and activity changes.
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.