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
What Is Mounjaro Jag? NHS Access in the UK
Mounjaro jag is the UK colloquial term for the Mounjaro (tirzepatide) injection — a prescription-only weight management medication available through both NHS specialist services and private online prescribing in the UK. This dual GIP and GLP-1 receptor agonist works differently from Wegovy (semaglutide) and may help regulate appetite and support weight loss when combined with lifestyle changes. Access routes, eligibility, and costs differ significantly depending on whether you pursue NHS or private prescribing. Understanding your options is essential for making an informed decision about treatment.
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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 and Eligibility for Mounjaro in the UK
In the UK, Mounjaro is licensed for weight management in adults, but NHS access is limited to specialist tier 3 weight management services — not standard GP prescriptions. You cannot request Mounjaro directly from your GP; instead, you must be referred to a specialist weight management service through your local Integrated Care Board (ICB).
- You may be eligible if you have a BMI of 30 or above (or 27+ with weight-related health conditions like type 2 diabetes, high blood pressure, or cardiovascular disease)
- For South Asian, Chinese, Black African, or Black Caribbean adults, lower BMI thresholds apply (eligibility may start at BMI 27.5+)
- NHS waiting lists for tier 3 services vary significantly by region — some areas have waiting times of 6–18 months or longer
- NICE has approved tirzepatide for use within NHS specialist services, but regional availability remains patchy
Use our free BMI calculator above to check whether you might meet the eligibility threshold for specialist assessment. Your GP can refer you to your local tier 3 service if appropriate.
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 Mounjaro Prescribing vs NHS Route
If NHS waiting lists are unacceptable or you don't meet local NHS criteria, private online prescribing offers faster access. Licensed UK prescribers assess you via online consultation and issue a prescription if clinically appropriate — typically within 24–48 hours. Private Mounjaro costs approximately £129–£320 per month depending on dose and provider.
The key difference: private access does not require NHS referral, but you pay upfront. NHS access is free once referred, but involves waiting and regional variation. Both routes require a valid prescription from a UK-licensed prescriber and dispensing by a GPhC-registered pharmacy. Neither route bypasses clinical assessment — both assess your eligibility, medical history, and suitability before prescribing.
Try our GLP-1 weight loss calculator to estimate potential weight loss outcomes at different Mounjaro doses, based on clinical trial data. This can help you understand realistic expectations before pursuing either NHS or private access.
- 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 through my NHS GP?
No — Mounjaro is only available through specialist tier 3 weight management services in the NHS, not standard GP prescriptions. You must be referred by your GP to your local specialist service. Private online prescribing offers faster access without NHS referral, but involves cost.
What is the difference between Mounjaro jag and Wegovy jag?
Both are injectable weight management medications, but Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist, whilst Wegovy (semaglutide) is a GLP-1-only agonist. Clinical trials suggest Mounjaro may produce slightly greater average weight loss (around 20.9% vs 14.9% body weight), though individual results vary significantly.
How long are NHS waiting lists for Mounjaro?
NHS waiting times vary by region — some areas have waits of 6–18 months or longer due to high demand and limited specialist capacity. Contact your local Integrated Care Board (ICB) to find out waiting times in your area. Private prescribing offers faster access but at private cost.
Am I eligible for Mounjaro on the NHS?
You may be eligible if you have a BMI of 30+, or 27–29.9 with weight-related health conditions (type 2 diabetes, hypertension, cardiovascular disease). Lower thresholds apply for South Asian, Chinese, Black African, and Caribbean adults. Your GP assesses whether specialist referral is appropriate for your circumstances.
Does NICE recommend Mounjaro?
Yes — NICE has approved tirzepatide (Mounjaro) for use within NHS specialist weight management services. However, NICE approval does not assures funding or availability in all regions. Access depends on your local ICB's commissioning decisions and capacity.
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.