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 12.5 mg Cost in the UK?
Mounjaro 12.5 mg is the second-highest dose of tirzepatide available in the UK for weight management. The cost of Mounjaro varies significantly depending on whether you access it through the NHS or privately. Private prescription costs typically range from £200–£300 per month at this dose, though prices vary between providers. NHS access through specialist weight management services is free at point of use, but availability depends on your local integrated care board (ICB) and current waiting lists. Understanding the full cost picture—including what's included in private pricing and NHS eligibility criteria—helps you make an informed decision about this prescription-only medication.
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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 Mounjaro Costs and What's Included
Private prescription costs for Mounjaro 12.5 mg typically range from £200–£300 per month, though this varies between GPhC-registered online pharmacies. A Mounjaro KwikPen contains four weekly doses (a one-month supply), so you're paying for the full pen. The 12.5 mg dose is reached during titration—you start at 2.5 mg and increase gradually over several weeks, so initial costs are lower as you progress through the lower doses (5 mg, 7.5 mg, 10 mg).
Private pricing typically includes the prescription assessment fee (usually £40–£80) and the medication cost combined. Some providers offer tiered pricing depending on dose, so the 12.5 mg dose may be more expensive per pen than lower doses. If you're eligible for NHS access through specialist services, that is free, but NHS availability remains limited in many regions with significant waiting lists. Compare costs and eligibility across private providers and check with your GP about NHS tier 3 weight management service availability in your area.
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 vs Private Access for Mounjaro
NHS access to Mounjaro is free at point of use but requires referral to a tier 3 specialist weight management service—your GP cannot prescribe it directly. NICE has approved tirzepatide (Mounjaro) for NHS use, but availability varies dramatically by region. Some ICBs have no current availability, while others have waiting lists of 12–24 months. Private access bypasses NHS waiting lists entirely: you complete an online clinical assessment with a UK-licensed prescriber, and if approved, your prescription is dispensed within days by a GPhC-registered pharmacy.
To check NHS availability, ask your GP for a referral to your local specialist weight management service. For private access, multiple online providers offer Mounjaro at varying price points. Calculate your estimated weight loss using our GLP-1 weight loss calculator to help weigh the cost investment against potential health benefits.
- 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.
Does the 12.5 mg dose cost more than lower doses?
Yes, generally. The 12.5 mg dose of Mounjaro in a KwikPen typically costs slightly more than the 5 mg or 10 mg pens from private providers, though the difference is usually modest (£5–£20 per pen). Since you titrate gradually, you'll pay lower costs at earlier doses (2.5 mg, 5 mg) before reaching 12.5 mg. Total cost depends on how long you stay at each dose—minimum 4 weeks per dose.
Can I get Mounjaro 12.5 mg free on the NHS?
Yes, if you meet eligibility criteria and are referred to a tier 3 specialist weight management service. However, NHS availability is severely limited with long waiting lists in most regions. Ask your GP for a referral to check if your local service can offer it. Private access is faster if you meet clinical criteria and can afford the cost.
Is Mounjaro cheaper than Wegovy in the UK?
Pricing is similar—both typically range £200–£300 monthly privately, depending on dose and provider. Mounjaro's 12.5 mg and Wegovy's 2.4 mg (maximum dose) are clinically different despite similar price points. Choose based on prescriber recommendation and individual clinical suitability, not price alone.
What's included in the monthly cost of Mounjaro?
Private pricing covers the Mounjaro KwikPen (one month's supply of four weekly injections), the prescription from a UK-licensed prescriber (usually included in the total quoted price), and dispensing by a GPhC-registered pharmacy. Some providers may separately itemise the clinical assessment fee. Check with your chosen provider for a transparent price breakdown.
Can I switch doses to reduce cost?
You cannot skip doses to save money—tirzepatide (Mounjaro) requires a structured dose titration for safety. You must spend a minimum of 4 weeks on each dose before increasing. Stopping early or skipping doses may reduce weight loss effectiveness and is not recommended. Discuss any cost concerns with your prescriber.
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.