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 Access in the UK
Mounjaro (tirzepatide) 15mg is the maximum recommended dose for weight management in the UK, but cost and access vary significantly depending on whether you pursue NHS or private prescription routes. Understanding your options, eligibility requirements, and what each route involves is essential before starting treatment. This guide explains how to access Mounjaro in the UK, realistic costs at the 15mg dose, and what the clinical assessment process entails.
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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.
UK Private Prescription Costs for Mounjaro 15mg
Private prescription costs for Mounjaro at the maximum 15mg dose typically range from £180 to £320 per month, depending on the prescribing service and pharmacy. Each KwikPen contains four weekly injections (a one-month supply), so you receive a new pen each month once you reach the 15mg maintenance dose after dose titration.
The 15mg dose is reached gradually — you start at 2.5mg and increase by 2.5mg every four weeks until reaching 15mg around week 21. This means your costs will be lower initially (around £130–£180 for starting doses) and increase as you titrate upwards. The 15mg maintenance phase typically costs in the £250–£320 range monthly, though some providers may offer competitive pricing.
- Online prescribing services assess your health through questionnaire and video consultation
- Costs may include the consultation fee (usually £15–£40) plus the medication cost
- Some services offer subscription models or bulk discounts
- Prices vary because different GPhC-registered pharmacies have different margins and supplier 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.
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NHS vs Private Access: Which Route is Right for You?
NHS access: Mounjaro may be available through NHS specialist weight management services (tier 3/4), but access is highly variable by region and typically involves waiting lists of several months to years. Your GP refers you to your local integrated care board's weight management service, which then assesses eligibility and prescribes if appropriate. You pay nothing for NHS prescriptions (standard prescription charge £11.90 in England, or nothing if eligible for free prescriptions).
Private access: Available now through online consultations with UK-licensed prescribers, without NHS referral. Faster access but you pay the full cost. Private online prescribing involves completing a health questionnaire, having a brief video or telephone consultation with a licensed prescriber, and receiving a prescription to a GPhC-registered pharmacy within 24–48 hours. Use our GLP-1 weight loss calculator to project potential outcomes at the 15mg dose alongside your cost calculations.
- 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 is the actual cost of Mounjaro 15mg per month in the UK?
Private prescription costs for Mounjaro 15mg typically range from £250–£320 per month once you reach the maintenance dose. Costs are lower during the dose titration phase (starting at around £130–£180 for 2.5mg). Each KwikPen contains four weekly injections. NHS costs are covered by standard prescription charges (£11.90 per item in England, or free if eligible), but NHS access varies significantly by region and involves waiting lists.
How long does dose titration take before reaching 15mg?
Mounjaro titration typically takes 20–21 weeks to reach the maximum 15mg dose. You start at 2.5mg and increase by 2.5mg every four weeks: weeks 1–4 (2.5mg), weeks 5–8 (5mg), weeks 9–12 (7.5mg), weeks 13–16 (10mg), weeks 17–20 (12.5mg), week 21+ (15mg). Your monthly costs will gradually increase during this period as you move to higher doses.
Can I get Mounjaro on the NHS through my GP?
Direct NHS prescribing through your GP is not standard. You'll need a referral to your local NHS tier 3 specialist weight management service, which then assesses whether Mounjaro is appropriate. Eligibility typically requires a BMI of 30 or above, or 27–29.9 with weight-related health conditions. Regional availability and waiting times vary significantly — some areas have long waiting lists or limited availability.
What happens during a private online consultation for Mounjaro?
You complete a detailed health questionnaire covering medical history, current medications, allergies, and lifestyle. A UK-licensed prescriber then reviews your information and may conduct a brief video or telephone consultation to confirm suitability. If approved, a prescription is issued to a GPhC-registered pharmacy, which dispenses the medication. The entire process typically takes 24–48 hours from consultation to dispatch.
Is Mounjaro 15mg more effective than lower doses?
Clinical trials showed that higher doses produce greater average weight loss — tirzepatide 15mg resulted in approximately clinically studied weight loss compared to 19.5% at 10mg in the SURMOUNT-1 trial. However, individual results vary significantly, and some people achieve their weight loss goals at lower doses. Many people tolerate lower doses better. Your prescriber will guide titration based on your response and side effects.
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.