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
Do I Qualify For Mounjaro On NHS?
Whether you can access Mounjaro (tirzepatide) on the NHS depends on your BMI, weight-related health conditions, and your local NHS service availability. The NHS has approved tirzepatide for weight management through specialist tier 3 and tier 4 services, but access varies significantly across regions. If you don't qualify through the NHS, or face long waiting lists, private prescription options are available in the UK. This guide explains the criteria, costs, and how to explore both routes.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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 Criteria For Mounjaro
To qualify for Mounjaro through the NHS, you typically need to meet these criteria:
- BMI of 30 or above (obesity), OR BMI of 27–29.9 (overweight) with at least one weight-related health condition
- Weight-related conditions include type 2 diabetes, prediabetes, high blood pressure, abnormal blood fats, obstructive sleep apnoea, or history of heart disease or stroke
- Ethnicity adjustment: If you are of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds may apply (from BMI 27.5 or above)
- Referral required: You must be referred to a specialist weight management service by your GP — Mounjaro is not prescribed in primary care
- Lifestyle support: NHS prescribing typically requires evidence of prior engagement with diet and exercise programmes
Once referred, you'll be assessed by a specialist team who will confirm whether the Mounjaro KwikPen is appropriate for your individual circumstances. NICE has approved tirzepatide for NHS use, but actual availability depends on your local Integrated Care Board (ICB) and current service capacity.
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 — Cost & Timeline
NHS route: Free at point of use, but referral to specialist services can take months. Some regions have waiting lists exceeding 12 months. Once approved, the medication itself is free, but you'll need regular monitoring appointments.
Private route: Available without NHS referral through UK-licensed online prescribers. Costs typically range from £129–£320 per month depending on your dose and provider. Online consultations usually take 24–48 hours. You'll still need a clinical assessment by a registered prescriber, but access is faster. Using our free GLP-1 weight loss calculator can help you estimate potential costs at different doses before pursuing either route.
- 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.
How do I know if my BMI qualifies me for Mounjaro on the NHS?
Calculate your BMI using your weight in kg and height in metres. Use our free BMI calculator above to find your exact BMI. If it's 30 or above, or 27–29.9 with a weight-related health condition, you may qualify. However, lower thresholds apply if you're of South Asian, Chinese, Black African, or Black Caribbean heritage.
How long does it take to get Mounjaro on the NHS?
Waiting times vary widely by region. After GP referral to a specialist weight management service, you might wait 6–18 months for an initial assessment. Some regions have shorter waits; others have significantly longer delays. Private access is typically 48 hours from initial consultation.
What's the difference between NHS and private Mounjaro prescriptions?
NHS prescriptions are free but require GP referral and specialist assessment, with potentially long waiting lists. Private prescriptions cost £129–£320 monthly, require an online consultation with a UK prescriber, but access is much faster. Both require clinical assessment; neither route is assured.
Can I switch from private Mounjaro to NHS Mounjaro?
It's possible but not automatic. If you're already taking private Mounjaro and want to switch to NHS, you'd need to discuss this with your GP. They would need to refer you to specialist services, which may involve reassessment and timing considerations. Private to NHS transitions are handled case-by-case.
Does being on Mounjaro affect my ability to access other NHS weight management support?
No. If prescribed through NHS specialist services, you'll receive integrated support including dietary advice, exercise programmes, and monitoring. Private prescribers will also recommend lifestyle changes alongside the medication, though direct NHS programme access may vary by region.
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.