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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Should I Try Mounjaro? Cost, Access & Eligibility in the UK
Wondering whether Mounjaro is right for you? The decision depends on your health profile, budget, and access route. Mounjaro (tirzepatide) is a prescription-only GLP-1 medication licensed in the UK for weight management in adults. It's available through the NHS via specialist weight management services or privately through online prescribers. Understanding the cost, eligibility criteria, and what the process involves will help you make an informed decision about whether to try it. This guide covers everything you need to know about accessing Mounjaro in the UK.
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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.
Mounjaro Cost & Access Routes in the UK
NHS access: Mounjaro is approved by NICE for use within NHS tier 3 and 4 specialist weight management services. However, NHS availability varies significantly by region. You'll need a referral from your GP to a specialist service, and waiting lists can be lengthy in many areas—sometimes several months to over a year depending on your local Integrated Care Board (ICB). Once assessed and approved, the NHS covers the cost of treatment.
Private access: You can obtain a prescription privately through a GPhC-registered online prescriber without waiting for NHS referral. Private treatment typically costs between £130–£300 per month depending on your dose. A Mounjaro KwikPen (four weekly injections) costs roughly £150–£200 privately. You'll complete an online health questionnaire, have a virtual consultation with a UK-licensed prescriber, and if approved, receive your prescription dispensed by a registered pharmacy. This route is faster but you pay out of pocket.
- NHS route: Free but potential long waits
- Private route: Faster access, costs £130–£300/month
- Both require clinical assessment and prescription
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.
Am I Eligible for Mounjaro?
You may be eligible for Mounjaro if you have a BMI of 30 or above, or a BMI of 27–29.9 with at least one weight-related health condition. Use our free BMI calculator above to check your personal BMI. Weight-related conditions include type 2 diabetes, prediabetes, high blood pressure, abnormal cholesterol, sleep apnoea, or cardiovascular disease. If you're of South Asian, Chinese, Black African, or Black Caribbean heritage, lower thresholds may apply (BMI 27.5+). You cannot take Mounjaro if you're under 18, pregnant, breastfeeding, or allergic to tirzepatide. Your GP or online prescriber will assess your suitability based on your individual health profile and medical history.
- 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 much does Mounjaro cost privately in the UK?
Private Mounjaro costs typically range from £130–£300 per month depending on your dose (2.5mg to 15mg) and the prescriber. A KwikPen contains four weekly injections. Costs vary between providers, so it's worth comparing different online prescribers. NHS treatment is free, but involves waiting for specialist referral and assessment.
Can I get Mounjaro through the NHS?
Yes, Mounjaro is approved by NICE for NHS specialist weight management services (tier 3 and 4). You'll need a GP referral to your local specialist service. Availability varies significantly by region and waiting times can be several months. Once approved, treatment is free. Check with your GP about availability in your area.
What happens during an online Mounjaro consultation?
You'll complete a health questionnaire covering your weight, medical history, current medications, and any previous weight management attempts. A UK-licensed prescriber reviews your answers and may ask follow-up questions via video or telephone. If appropriate, they'll issue a prescription, which is then dispensed by a GPhC-registered pharmacy. The entire process typically takes 24–48 hours.
How do I know if Mounjaro is right for me?
Mounjaro may be suitable if you have a BMI of 30+ (or 27+ with weight-related health conditions) and want to try a prescription weight loss medication alongside diet and exercise changes. Use our GLP-1 weight loss calculator to explore potential outcomes. However, only a healthcare professional can assess your individual suitability based on your health, medications, and medical history.
Is Mounjaro the same as Wegovy?
No. Both are injectable weight loss medications, but Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist, while Wegovy (semaglutide) is a GLP-1 agonist only. Mounjaro typically shows slightly higher average weight loss in clinical trials. Both are prescription-only and require clinical assessment. Your prescriber can help determine which is more appropriate for you.
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.