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 15mg — Cost and How to Access in the UK
Mounjaro 15mg (tirzepatide) is the maximum dose for weight management in the UK, typically reached after 20 weeks of dose titration. The cost varies significantly depending on whether you access it through the NHS or privately. This guide explains current UK pricing, how to get a prescription, and what to expect from the application process. Understand your options and eligibility before deciding which route is right for you.
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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.
Private Prescription Cost for Mounjaro 15mg in the UK
Private prescription costs for Mounjaro 15mg typically range from £200 to £320 per month, depending on the provider and whether you're starting from a lower dose or already established on treatment. Each KwikPen contains four weeks' supply (four injections), so monthly cost represents one pen.
- Costs vary between GPhC-registered online pharmacies and private weight management clinics
- Some providers offer tiered pricing based on dose — lower doses cost less than the maximum 15mg dose
- Many providers require an initial online clinical assessment (typically £50–£150), separate from medication costs
- Prescriber consultation fees may also apply if using independent weight management services
Private access works quickly — most people receive their first prescription within 1–2 weeks of consultation. This contrasts with NHS specialist services, where waiting lists in many regions exceed 6–12 months. When budgeting for Mounjaro 15mg privately, allow for the first month's higher cost (assessment + prescription + medication) before settling into monthly subscription costs.
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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.
NHS vs Private Access — Which Route is Right for You?
NHS route: Mounjaro is available through NHS specialist tier 3/4 weight management services following NICE approval. However, access is limited by regional availability and waiting lists. Most people must be referred by their GP, and availability varies significantly across integrated care boards (ICBs). Wait times commonly reach 6–18 months in many areas.
Private route: Prescription through a UK-licensed prescriber via online consultation, dispensed by a GPhC-registered pharmacy. No GP referral needed. Faster access (1–2 weeks) but you pay the full cost. Eligibility assessment still applies — prescribers will review your BMI, health conditions, and medical history to confirm suitability, similar to the NHS process.
Use our free BMI calculator to check your starting point, and our GLP-1 weight loss calculator to explore projected outcomes at the 15mg dose.
NHS route: Mounjaro is available through NHS specialist tier 3/4 weight management services following NICE approval. However, access is limited by regional availability and waiting lists. Most people must be referred by their GP, and availability varies significantly across integrated care boards (ICBs). Wait times commonly reach 6–18 months in many areas.
Private route: Prescription through a UK-licensed prescriber via online consultation, dispensed by a GPhC-registered pharmacy. No GP referral needed. Faster access (1–2 weeks) but you pay the full cost. Eligibility assessment still applies — prescribers will review your BMI, health conditions, and medical history to confirm suitability, similar to the NHS process.
Use our free BMI calculator to check your starting point, and our GLP-1 weight loss calculator to explore projected outcomes at the 15mg dose.
- 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 reach the Mounjaro 15mg dose?
Mounjaro follows a structured dose titration schedule starting at 2.5mg and increasing every 4 weeks. Reaching 15mg typically takes 20–24 weeks (approximately 5–6 months). You cannot jump directly to 15mg — each dose level must be maintained for a minimum of 4 weeks to assess tolerance and efficacy before escalating. Your prescriber will manage this schedule.
Is Mounjaro 15mg more expensive than lower doses?
Yes. Private costs increase with dose strength. A 5mg or 10mg dose typically costs £150–£200 per month, while 15mg costs £250–£320 per month. However, you don't pay the maximum dose price initially since you start lower and titrate up gradually over months. Total first-year cost depends on how quickly you escalate and where you source your prescription.
Can I get Mounjaro 15mg through my NHS GP?
Not directly from your GP. Standard GP practices do not prescribe Mounjaro for weight management. You must be referred to a specialist NHS tier 3 or tier 4 weight management service by your GP. Even then, Mounjaro availability depends on your local integrated care board (ICB) and current service capacity. Waiting lists are extensive in most regions.
What's included in the private prescription cost?
The monthly cost typically covers the medication only (the KwikPen). Initial costs may also include the online clinical assessment (£50–£150) and prescriber consultation fee (£0–£50 depending on provider). Ongoing follow-up consultations may be charged separately or included in subscription models. Always clarify pricing before committing to a provider.
Why is Mounjaro 15mg more expensive than Wegovy at maximum dose?
Mounjaro (tirzepatide) uses a dual GIP/GLP-1 mechanism compared to Wegovy's single GLP-1 pathway. Manufacturing, research, and market positioning differ between the two. Wegovy maximum dose (2.4mg) is also lower than Mounjaro's 15mg, affecting per-dose formulation costs. Prices also vary by provider, region, and supply factors.
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.