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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How Much Does Mounjaro 15mg Cost in the UK?
Mounjaro (tirzepatide) 15mg is the maximum licensed dose available in the UK, but pricing varies significantly between NHS and private access routes. The 15mg dose is typically reached after dose titration over several months, and costs depend entirely on whether you're accessing the medication through NHS specialist weight management services or through private prescription channels. This guide explains UK pricing, eligibility, and how to access Mounjaro at the highest therapeutic dose.
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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.
NHS Access and NICE Approval for Mounjaro 15mg
NICE has approved tirzepatide (Mounjaro) for weight management within NHS specialist services, but access is limited to tier 3 and tier 4 weight management services, not standard GP prescription. If you're eligible for NHS Mounjaro treatment, you won't pay for the medication itself — NHS prescriptions are dispensed under standard prescription charges (currently £10.65 per item in England, free in Scotland and Wales for eligible patients).
However, NHS access is heavily region-dependent. Availability varies by Integrated Care Board (ICB), and many areas have extremely long waiting lists — sometimes 12 to 24 months or longer. Your GP must refer you to a specialist tier 3 weight management service, and the service will assess whether Mounjaro is appropriate for you. The 15mg dose is the maximum, but you'll start at 2.5mg and increase gradually (dose titration) over approximately 16+ weeks.
- NHS cost: £10.65 per prescription (England); free (Scotland/Wales)
- Requires specialist service referral
- Significant waiting lists in most areas
- NICE guidance supports use for eligible adults
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 15mg Pricing in the UK
Private prescription costs for Mounjaro 15mg range from approximately £250 to £320 per month, depending on the prescribing provider and pharmacy. A single KwikPen contains four weekly doses, so costs are typically quoted per pen rather than per individual injection. Private access means no NHS waiting list — you can begin the dose titration process immediately after a remote clinical assessment with a UK-licensed prescriber.
At 15mg (the maximum dose), your monthly cost will be at the higher end because each pen costs more than lower doses. Some private providers offer slightly discounted rates for bulk ordering or ongoing subscriptions. You'll need to budget for several months of treatment at lower doses (2.5mg, 5mg, 7.5mg, 10mg, 12.5mg) before reaching 15mg, so total upfront costs vary. Private prescriptions are issued by GPhC-registered online pharmacies following clinical assessment.
Private prescription costs for Mounjaro 15mg typically range from £250–£320 per month, though prices vary between providers. Each KwikPen contains four weekly doses, so you'll need roughly one pen per month at the maximum dose. Unlike the NHS, private access means no waiting list — treatment can begin after a clinical assessment, but you'll still follow dose titration starting at 2.5mg and progressing over 16+ weeks. The full journey to 15mg will cost considerably more due to costs at lower doses beforehand. Costs may be slightly lower with some providers offering package pricing for ongoing treatment or if tirzepatide becomes available as a generic in future, though this remains unlikely in the near term.
- 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 15mg available on the NHS for free?
Mounjaro is available through NHS specialist weight management services (tier 3/4) for eligible adults, subject to NICE guidance. If prescribed by the NHS, you'll pay standard prescription charges (£10.65 per item in England; free in Scotland and Wales). However, NHS access is very limited due to long waiting lists and regional availability differences. Most areas have 12–24 month waits.
How much does a single Mounjaro 15mg pen cost privately?
A single KwikPen of Mounjaro 15mg costs approximately £250–£320 privately, depending on the pharmacy. Each pen contains four weekly doses, so this typically covers one month of treatment. Prices may vary between GPhC-registered online pharmacies, so it's worth comparing providers.
What's the difference between Mounjaro and tirzepatide?
Mounjaro is the brand name for tirzepatide — they're the same medication. Tirzepatide is a dual GIP and GLP-1 receptor agonist that may help with weight loss by reducing appetite and supporting feelings of fullness. Mounjaro is the only brand name available in the UK for this active ingredient.
How long does it take to reach the 15mg Mounjaro dose?
Dose titration typically takes 16+ weeks to reach 15mg. You start at 2.5mg (weeks 1–4), increase to 5mg (weeks 5–8), 7.5mg (weeks 9–12), 10mg (weeks 13–16), 12.5mg (weeks 17–20), then 15mg (week 21+). Each dose requires a minimum four-week period before escalating, so reaching the maximum dose takes around four months or longer.
Does private Mounjaro 15mg cost include GP visits?
Private Mounjaro prescriptions are issued following a remote clinical assessment with a UK-licensed prescriber — not your GP. The cost quoted (£250–£320 per month) is for the medication only. Some providers may offer optional GP support or monitoring services separately, but these vary by clinic and aren't always included in the base prescription price.
Ready to take control of your weight loss journey?
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