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 on the NHS — UK Cost and Access Guide
Mounjaro (tirzepatide) is available on the NHS in the UK, but access is limited and varies significantly by region. If you're considering this prescription weight management injection, you'll need to understand how NHS access works, what the private route costs, and how long the process typically takes. This guide explains your options and what real users report about their experience 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.
NHS Access vs Private Routes — What's the Difference?
NHS access to Mounjaro is through specialist tier 3 weight management services, not your GP. You'll typically need a referral from your GP to a regional specialist weight management centre, where clinicians assess your eligibility and manage your treatment. NICE (National Institute for Health and Care Excellence) has approved tirzepatide for use within NHS specialist services for adults with a BMI of 30 or above, or 27–29.9 with weight-related health conditions.
Private access is faster but costs money. You can obtain a prescription through an online consultation with a UK-licensed prescriber (without an NHS referral), and collect your medication from a GPhC-registered pharmacy. Private costs typically range from £129–£320 per month depending on your dose — the Mounjaro KwikPen contains 4 weeks' supply. Many users report that NHS waiting lists can be extremely long (months to years in some regions), while private access is available within days if you're eligible.
Our GLP-1 weight loss calculator can help you estimate potential outcomes at different Mounjaro doses to inform your decision.
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.
The Online Consultation Process and What to Expect
If choosing the private route, you'll complete an online health questionnaire and speak with a UK-licensed prescriber via video or phone. They'll assess your medical history, current medications, BMI, and weight-related health conditions to determine if Mounjaro is suitable. If approved, they'll issue a prescription that you collect from the pharmacy.
The process typically takes 24–48 hours from consultation to prescription. You'll receive your Mounjaro KwikPen in the post, complete with injection instructions. Storage is straightforward: unopened pens stay in the fridge (2–8°C), and once you start, you can keep your pen at room temperature (below 30°C) for up to 30 days. Real-world reviews highlight that having a clear clinical assessment and written guidance on side effects, dose escalation, and storage is reassuring, especially for first-time users.
- 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 long does it take to get Mounjaro on the NHS?
NHS waiting times vary dramatically by region. Some specialist weight management services have waiting lists of 6–12 months or longer due to high demand. Initial assessment appointments may take several months, and if approved, supply can vary. Private routes are typically much faster — often within 48 hours of consultation.
What's the cost of Mounjaro on the NHS?
Mounjaro is free on the NHS if you access it through a specialist tier 3 service and meet eligibility criteria. However, you must be referred by your GP and approved for specialist care. Private prescriptions cost approximately £129–£320 per month depending on your dose level, plus any consultation fee.
Am I eligible for Mounjaro on the NHS?
You may be eligible if you have a BMI of 30 or above, or 27–29.9 with weight-related conditions such as type 2 diabetes, high blood pressure, or cardiovascular disease. South Asian, Chinese, Black African, and Black Caribbean adults may qualify at slightly lower BMI thresholds. Your GP can assess your eligibility and refer you to specialist services.
Can I switch from Wegovy to Mounjaro?
Yes, some users and clinicians consider switching between GLP-1 medications. Mounjaro is a dual GIP+GLP-1 agonist (different mechanism) compared to Wegovy's single GLP-1 action. Any medication change must be managed by your prescriber — never stop or switch without medical guidance. The approximate dose equivalence is rough, and your prescriber will advise on safe switching.
What do real users say about accessing Mounjaro in the UK?
Common themes in user reviews include frustration with NHS waiting lists, appreciation for faster private access, and surprise at the cost of private prescriptions. Many report that having professional clinical guidance during assessment is valuable. Most emphasise that Mounjaro works best alongside diet and physical activity changes — medication alone doesn't studied results.
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.