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 5mg Cost in the UK — Your Complete Guide
Mounjaro 5mg is the first maintenance dose of tirzepatide, a prescription-only weight loss injection licensed in the UK. If you're searching for affordable access to Mounjaro, this guide covers NHS eligibility, private costs, and what to expect at the 5mg dose. The cost varies significantly depending on whether you access it through the NHS or privately, and availability depends on your circumstances and location.
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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.
How Much Does Mounjaro 5mg Cost in the UK?
NHS cost: If prescribed through an NHS tier 3 specialist weight management service, Mounjaro is free at the point of care (no charge to you). However, NHS access is limited and availability varies significantly by region. Waiting lists can be lengthy — sometimes months or years in some areas. Your GP would need to refer you to your local specialist weight management service, and the service would assess your eligibility.
Private cost: Through private online prescribing services, Mounjaro 5mg typically costs between £129–£180 per month, depending on the provider. Each KwikPen contains 4 weeks of doses. Private prescriptions require an online clinical assessment with a UK-licensed prescriber. If the prescriber deems it appropriate, they'll issue a prescription that you collect from a GPhC-registered pharmacy.
Use our free GLP-1 weight loss calculator to estimate potential results at the 5mg dose and understand whether this medication might be suitable for your circumstances.
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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.
What Happens at the 5mg Dose?
The 5mg dose is not the starting dose — you'll begin at 2.5mg for the first 4 weeks, then move to 5mg for weeks 5–8. At 5mg, many people experience the weight loss effects of Mounjaro becoming more noticeable. Clinical trial data shows that participants on 5mg lost an average of approximately 15% of their body weight over 72 weeks, though individual results vary significantly. The 5mg dose is often effective for weight loss, but some people increase to 7.5mg or higher depending on tolerability and response.
Common side effects at 5mg include nausea, constipation, or diarrhoea — these typically improve as your body adjusts. Track your progress alongside lifestyle changes using our free progress tracker.
- 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.
Is Mounjaro 5mg cheaper on the NHS than private?
Yes — on the NHS, Mounjaro is free. Privately, 5mg costs £129–£180/month. However, NHS access is limited, with long waiting lists in many regions. Your GP must refer you to a specialist tier 3 weight management service, and they'll assess eligibility based on your BMI and health conditions.
Can I get Mounjaro 5mg on the NHS in the UK?
Mounjaro (tirzepatide) is approved by NICE for NHS use in specialist weight management services. However, access varies by region and is subject to waiting lists. You'll need a GP referral to your local specialist service, which will assess whether you meet eligibility criteria (typically BMI ≥30, or BMI 27–29.9 with weight-related health conditions).
Why is 5mg not the starting dose?
Mounjaro uses a gradual dose escalation to help your body adjust and reduce side effects. You start at 2.5mg for 4 weeks, then increase to 5mg. Escalating slowly helps minimise nausea and gastric symptoms, making the treatment more tolerable long-term.
What's the difference between Mounjaro 5mg and other doses?
Mounjaro comes in doses from 2.5mg to 15mg weekly. The 5mg dose is a maintenance dose offering moderate weight loss (average ~15% body weight in trials). Higher doses (10mg, 15mg) may offer greater weight loss, but individual response varies. Your prescriber will escalate based on your tolerability and response.
Can I buy cheap Mounjaro online without a prescription?
No — Mounjaro is prescription-only in the UK. You cannot legally buy it without a valid UK prescription from a licensed prescriber. Any online seller claiming to sell Mounjaro without a prescription is operating illegally. Always use a GPhC-registered pharmacy following a proper clinical assessment.
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.