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 15 mg Mounjaro Cost in the UK?
The cost of 15 mg Mounjaro in the UK varies significantly depending on whether you access it through the NHS or privately. The maximum dose of tirzepatide (Mounjaro) is 15 mg once weekly, typically used after dose titration from lower doses. NHS access is limited to specialist weight management services with long waiting lists in many regions, while private prescribing offers faster access but at a cost. Understanding your options, eligibility, and pricing will help you make an informed decision about whether this medication 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.
Mounjaro 15 mg Pricing — NHS vs Private Access
Private pricing (most common route): A single 15 mg Mounjaro KwikPen (4 weeks supply, 4 injections) typically costs between £240–£320 in the UK through private prescribing services. This works out to approximately £60–£80 per weekly injection at maximum dose. Costs vary between providers and may include consultation fees (usually £20–£50). Some private services offer subscription or bundle discounts for ongoing treatment.
NHS pricing: If prescribed through an NHS specialist weight management service, Mounjaro would be provided at no direct cost to you under your prescription exemption. However, NHS access to tirzepatide is extremely limited. NICE approved tirzepatide for NHS use in specialist tier 3/4 weight management services, but availability varies dramatically by region and waiting lists can extend 12–24 months. Your regional Integrated Care Board (ICB) determines local access criteria and availability.
- Each KwikPen contains exactly 4 injections (4 weeks of treatment)
- You will need a prescription from a UK-licensed prescriber
- Private prescribing requires an online clinical assessment
- Treatment is ongoing — you do not stop at 15 mg if it is working
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.
Understanding Mounjaro Dose Escalation and Total Treatment Cost
Most people do not start at 15 mg. The standard dose titration schedule begins at 2.5 mg and increases every 4 weeks (2.5 mg → 5 mg → 7.5 mg → 10 mg → 12.5 mg → 15 mg). This means your first month costs less than your fifth month. Over a 24-week titration to reach 15 mg, your total cost would be approximately £1,200–£1,600 with private providers. Long-term treatment is typically ongoing, so budget for continuous costs. Many people find the investment worthwhile given the clinical trial results showing an average of clinically studied weight loss at this dose, though individual results vary significantly and depend on adherence alongside diet and activity changes.
- 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.
Can I get 15 mg Mounjaro free on the NHS in the UK?
Mounjaro is available free on the NHS through specialist weight management services (tier 3/4), but access is extremely limited. Your GP would need to refer you, and availability depends on your region. Waiting lists are typically 12–24+ months. Most people seeking Mounjaro access it privately, where you need a prescription from a UK-licensed prescriber following a clinical assessment.
What is included in the private cost of Mounjaro?
The cost usually covers the KwikPen prescription (4 injections) plus a clinical consultation fee (£20–£50). It does not include GP follow-ups or blood tests, which you may need to arrange separately. Some providers offer bundle pricing if you commit to multiple months. Always check what is included before purchasing.
Why is 15 mg Mounjaro more expensive than lower doses?
It is not — the price per KwikPen is the same regardless of dose strength. You are paying for the device and medication inside. However, it takes 6 months to reach 15 mg through titration, so your total upfront cost is higher. Once you reach 15 mg, weekly costs stabilise.
Can I use my private health insurance to cover Mounjaro?
Most UK private health insurance policies do not cover weight management medications like Mounjaro. Check your policy document or contact your provider directly. Some specialist weight management clinics may offer payment plans to spread the cost over several months.
How do I know if I am eligible for Mounjaro at any price?
You need a BMI of 30 or above, or 27–29.9 with weight-related health conditions (diabetes, high blood pressure, sleep apnoea, cardiovascular disease). A prescriber will assess your full health history during a clinical consultation. Certain people (under 18, pregnant, or with specific medical conditions) cannot take it. Your GP can also refer you to NHS specialist services to discuss eligibility.
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.