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
Mounjaro Cost Per Month in the UK
Mounjaro (tirzepatide) costs vary significantly in the UK depending on whether you access it through the NHS or privately. Private prescription costs typically range from £150–£320 per month depending on your dose, while NHS access is free but involves lengthy waiting lists and regional variation. Understanding both routes — and what factors affect pricing — helps you make an informed decision about weight loss treatment. Our GLP-1 weight loss calculator can help you estimate potential outcomes alongside cost considerations.
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.
Private Mounjaro Costs in the UK
If you choose private access, Mounjaro costs between approximately £150–£320 per month depending on your dose and the provider. A single KwikPen contains four weekly injections (one month supply). Starting doses (2.5–5 mg) are typically at the lower end of this range, whilst maintenance doses (10–15 mg) cost more. Most private UK prescribers require an online clinical assessment before issuing a prescription — usually costing £30–£50 separately. This assessment confirms you meet eligibility criteria: BMI of 30 or above, or 27–29.9 with weight-related health conditions. Private prescription Mounjaro is dispensed by GPhC-registered pharmacies and does not require an NHS referral, meaning you can start within days rather than months. Your prescriber will discuss dose titration (gradual increases every 4 weeks) and potential costs of escalating doses.
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 and What to Expect
On the NHS, Mounjaro is free but only available through tier 3 specialist weight management services following a GP referral. Waiting lists vary dramatically by region — some areas have 6-month waits, others 2+ years. NHS services manage your full care pathway, including blood tests, dose adjustments, and monitoring for side effects. Private access bypasses NHS waiting lists entirely: you complete an online consultation with a UK-licensed prescriber, provide relevant health information, and receive a prescription if clinically appropriate. You then order through a GPhC-registered pharmacy. Both routes are legitimate in the UK; your choice depends on whether you prioritise speed (private) or integrated NHS care (NHS). Use our free BMI calculator to confirm your eligibility before pursuing either route.
- 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 does a single Mounjaro KwikPen cost in the UK privately?
A single KwikPen (4 weekly injections) costs £150–£320 depending on dose strength. Starting doses (2.5–5 mg) are typically £150–£200 per pen, whilst higher maintenance doses (10–15 mg) range £250–£320. Costs vary between private providers, so it's worth comparing options.
Is Mounjaro free on the NHS in the UK?
Yes, Mounjaro is free on the NHS, but only through specialist tier 3 weight management services following a GP referral. Availability and waiting lists vary significantly by region — some areas have shorter waits than others. Ask your GP about local services in your area.
How long does it take to start Mounjaro privately vs NHS?
Privately, you can typically start within 3–7 days after your online consultation and prescription approval. On the NHS, waits depend on your region but commonly range from 6 months to 2+ years. Private access is faster; NHS access is free but involves waiting.
What is tirzepatide and how does it differ from semaglutide (Wegovy)?
Tirzepatide (Mounjaro) is a dual GIP and GLP-1 receptor agonist, whilst semaglutide (Wegovy) is a GLP-1 agonist only. Clinical trials suggest Mounjaro may support slightly greater average weight loss, but individual results vary considerably. Both are prescription-only UK-licensed medications.
Do I need a clinical assessment before starting Mounjaro privately?
Yes, all private Mounjaro prescriptions require an online clinical assessment (£30–£50). Your prescriber reviews your medical history, current medications, BMI, and any weight-related health conditions to confirm eligibility before issuing a prescription.
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.