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- 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 15 Mg in the UK — Cost, Access & Prescription Guide
Mounjaro 15 mg is the maximum dose of tirzepatide available in the UK as a prescription-only weight management injection. This guide explains how to access Mounjaro 15 mg, what it costs through private prescribing, NHS eligibility, and the clinical assessment process. Whether you're considering starting Mounjaro or exploring your options, understanding the cost and access routes will help you make an informed decision about your weight management journey.
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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 15 Mg Private Cost in the UK
Mounjaro 15 mg is available through private online prescribing services in the UK following a clinical assessment. Private costs typically range from £180–£320 per month depending on the provider and whether you purchase a single dose or monthly supply. Each Mounjaro KwikPen contains 4 weeks of injections at your prescribed dose.
- Prices vary between GPhC-registered pharmacies — shopping around may reveal different costs
- Monthly supply (4 pens at 15 mg) represents the maximum maintenance dose cost
- Some providers offer tiered pricing or subscription discounts for regular users
- Private prescriptions are valid for 6 months, giving you flexibility to source medication at different times
- Prescription fees (online consultation) are typically £20–£60 on top of medication costs
Costs do not include optional lifestyle support programmes or dietary counselling, which some providers offer separately.
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 Access vs Private Route — Which is Right for You?
NHS access to Mounjaro 15 mg is through specialist tier 3/4 weight management services following referral from your GP. NICE has approved tirzepatide for NHS use, but availability varies significantly by region and waiting lists can be 6–18 months. Private access requires an online clinical assessment with a UK-licensed prescriber — results are usually available within 24 hours. If cost is a barrier, ask your GP about NHS routes. If you want faster access and can afford private costs, the online prescribing route is immediate. Both routes require you to be eligible (BMI ≥30, or ≥27 with weight-related health conditions) and committed to lifestyle changes alongside the medication.
- 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.
What's the difference between Mounjaro 15 mg and other doses in cost?
Mounjaro 15 mg is the highest dose, so private costs are typically at the upper end of the price range (£250–£320/month). Lower doses like 5 mg or 10 mg may cost £150–£200/month. Costs vary by provider, so compare online before committing.
Can I get Mounjaro 15 mg on the NHS for free?
Potentially, yes — but only through NHS specialist weight management services after referral from your GP. Availability and waiting times vary by region. Contact your local ICB or ask your GP about tier 3 weight management services in your area.
How long does the online prescription process take?
Most UK online prescribing services deliver results within 24 hours. You'll complete a health questionnaire, a prescriber reviews it, and if approved, your prescription is sent to a GPhC-registered pharmacy for dispensing. Delivery typically takes 2–5 working days.
Is Mounjaro 15 mg the dose everyone uses?
No. Most people start at 2.5 mg and gradually increase over 16+ weeks. The 15 mg dose is the maximum maintenance dose, typically reached after several months of dose escalation. Your prescriber will recommend the right starting point for you.
What should I check when comparing Mounjaro 15 mg costs online?
Compare medication cost, prescription fee, delivery time, and whether ongoing support is included. Check the provider is GPhC-registered and the prescriber is a UK-licensed doctor or nurse. Read recent reviews and confirm they're legitimate before paying.
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.