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
What Are Mounjaro Costs in the UK?
Mounjaro (tirzepatide) costs vary significantly depending on whether you access it through the NHS or privately in the UK. Through the NHS, the medication is free at the point of use if prescribed by a specialist tier 3 weight management service, though availability is limited and varies by region. Private tirzepatide costs typically range from £150 to £320 per month depending on your dose and the prescribing provider. Understanding your options helps you make an informed decision about weight management treatment.
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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 and Eligibility for Mounjaro
NHS access to Mounjaro is limited and regionally variable. NICE has approved tirzepatide for use within specialist weight management services, but prescription through the NHS typically requires referral to a tier 3 or tier 4 service. Eligibility criteria include a BMI of 30 kg/m² or above, or 25–29.9 kg/m² with weight-related health conditions (type 2 diabetes, hypertension, dyslipidaemia, sleep apnoea, or cardiovascular disease). For South Asian, Chinese, Black African, or Black Caribbean adults, lower BMI thresholds of 27.5 kg/m² or above may apply. Waiting lists for NHS specialist services can be lengthy—often 6–18 months in many areas depending on your ICB (Integrated Care Board). When prescribed through the NHS, there is no cost to you, but you cannot choose the dose or timing; your prescriber determines this.
Check our free BMI calculator above to see if you meet the initial eligibility threshold for weight management support.
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 Costs and Access
Private Mounjaro costs range from approximately £150 to £320 per month depending on your starting dose and the provider. The mounjaro KwikPen contains 4 weeks of treatment (one dose per week), so monthly costs reflect the price of a single pen. Costs typically increase as you titrate to higher doses—starting doses (2.5 mg) cost less than maximum doses (15 mg). Private access is available through GPhC-registered online prescribing services following a clinical assessment. You do not need an NHS referral. Payment is typically required upfront, and costs are not covered by standard health insurance in the UK. Some private providers offer dose titration flexibility, allowing you to progress at your own pace alongside reduced-calorie diet and increased physical activity.
Use our GLP-1 weight loss calculator to estimate potential results and help assess whether treatment is right for you.
- 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.
Is Mounjaro free on the NHS in the UK?
Yes, Mounjaro is free at the point of use if prescribed through an NHS specialist tier 3 weight management service. However, NHS access is limited and availability varies significantly by region. You typically require a GP referral to a specialist service, and waiting lists can be 6–18 months. Private tirzepatide costs £150–£320 per month.
What is the cost of a Mounjaro KwikPen?
A single Mounjaro KwikPen (containing 4 weekly doses) costs approximately £150–£320 privately depending on the dose strength. Starting doses (2.5 mg) are typically less expensive than maximum doses (15 mg). Costs vary between private prescribing providers.
Can I get Mounjaro prescribed privately without NHS waiting lists?
Yes. Private Mounjaro is available through GPhC-registered online prescribing services following a clinical assessment. You do not need an NHS referral. The entire process—assessment to prescription—typically takes 1–5 days, though you must meet clinical eligibility criteria.
Who is eligible for Mounjaro treatment in the UK?
Adults with a BMI of 30 kg/m² or above, or 27–29.9 kg/m² with weight-related health conditions (diabetes, hypertension, sleep apnoea, cardiovascular disease) may be eligible. Lower thresholds apply for South Asian, Chinese, Black African, or Black Caribbean backgrounds. Your GP or prescriber will assess suitability based on your individual health.
What's the difference between NHS and private Mounjaro costs?
NHS Mounjaro is free if prescribed, but involves lengthy waiting lists and limited regional availability. Private Mounjaro costs £150–£320 monthly but offers quicker access (days rather than months) and dose flexibility. Neither private nor NHS options are covered by standard UK health insurance.
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.