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
Free tracker included with every download this week
How Much Does 15mg Mounjaro Cost in the UK?
Finding affordable Mounjaro 15mg in the UK depends on whether you access it through the NHS or privately. The 15mg dose is Mounjaro's maximum strength, typically reached after several weeks of dose titration starting from 2.5mg. NHS access is limited and varies significantly by region through specialist tier 3 weight management services, while private prescriptions through UK-licensed online pharmacies range from approximately £150–£320 per month depending on your prescriber and pharmacy. Use our free GLP-1 weight loss calculator to explore how different doses of Mounjaro might support your weight management goals.
10,000+ calculations today · NHS-aligned thresholds · 100% free
Calculate Your BMI Instantly
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 to Mounjaro 15mg in the UK
NHS eligibility for Mounjaro requires referral to a tier 3 specialist weight management service, typically from your GP. You must have a BMI of 30 or above, or 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or sleep apnoea. For South Asian, Chinese, Black African, or Black Caribbean adults, lower thresholds may apply (BMI 27.5+).
NICE has approved tirzepatide (Mounjaro) for use within NHS specialist services, but NHS availability is extremely limited. Many regions have long waiting lists (months to years), and some areas have no Mounjaro provision at all. Even when available, the NHS typically prescribes at lower doses initially, with escalation managed over weeks. Your GP can discuss NHS options, but availability depends entirely on your local Integrated Care Board (ICB) and whether your area commissions this treatment.
- Referral required from GP to tier 3 service
- Assessment by specialist multidisciplinary team
- NHS cost: free at point of use (but limited availability)
- Waiting times: highly variable by region
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 — UK Costs and Access
Private access to Mounjaro is faster and more accessible across the UK. Costs typically range from £150–£320 per month for 15mg pens, depending on your prescriber and pharmacy. A KwikPen contains 4 weekly injections (28 days supply). To access privately, you complete an online clinical assessment with a UK-licensed prescriber, who reviews your health history, BMI, and medical conditions to confirm eligibility. If approved, a prescription is issued and dispensed by a GPhC-registered pharmacy.
The 15mg dose is usually reached after dose titration, so your first month cost will be lower (starting at 2.5mg). Try our GLP-1 weight loss calculator to project potential weight loss at the 15mg dose, and use our BMI calculator to confirm your eligibility based on current weight and height.
- 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 15mg Mounjaro on the NHS in the UK?
NHS access to Mounjaro exists through tier 3 specialist weight management services, but availability is extremely limited. Most regions have waiting lists of many months or years. You need referral from your GP and must meet BMI criteria (30+ or 27–29.9 with health conditions). Even if available, the NHS usually starts at lower doses and escalates gradually. Check with your GP about your local availability.
How much does 15mg Mounjaro cost privately in the UK?
Private Mounjaro typically costs £150–£320 per month for a 15mg KwikPen (4 weekly injections). Cost varies by prescriber and pharmacy. However, you will start on a lower dose (2.5mg) and titrate up over weeks, so your initial months cost less. Once you reach 15mg maintenance, expect to pay toward the higher end of this range.
What is the difference between NHS and private Mounjaro in the UK?
NHS Mounjaro is free but availability is limited and waiting times are long (months to years in many regions). Private Mounjaro costs £150–£320/month but is faster to access (typically 1–2 weeks from assessment to first injection) and available nationwide. Both require clinical assessment; both are prescription-only.
How long does it take to reach the 15mg Mounjaro dose?
Mounjaro dose titration takes approximately 20 weeks (5 months). You start at 2.5mg for 4 weeks, then escalate by 2.5mg every 4 weeks: 5mg (weeks 5–8), 7.5mg (weeks 9–12), 10mg (weeks 13–16), 12.5mg (weeks 17–20), and finally 15mg from week 21 onwards. Your prescriber may adjust this timeline based on your response.
Is 15mg Mounjaro the maximum dose?
Yes, 15mg once weekly is the maximum approved dose of Mounjaro (tirzepatide) in the UK. Clinical trials showed an average weight loss of approximately 20.9% of body weight at this dose over 72 weeks, alongside a reduced-calorie diet and increased physical activity. Individual results vary significantly.
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.