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 Mounjaro Cost in the UK?
Mounjaro (tirzepatide) costs vary significantly in the UK depending on whether you access it through the NHS or privately. Most people find private online prescribing is the fastest route to access this GLP-1 receptor agonist weight loss injection, though costs typically range from £129 to £320 per month depending on your dose. NHS access is free but involves waiting lists and regional availability challenges. Understanding both routes helps you make an informed decision about this once-weekly injection for weight management.
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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.
Private Mounjaro Pricing in the UK
Private prescription costs for tirzepatide (Mounjaro) in the UK typically range from £129 to £320 per month. The exact cost depends on your starting dose and whether your prescriber increases it over time. Initial doses (2.5 mg) are usually cheaper than maintenance doses (15 mg).
- 2.5 mg dose: approximately £129–£160 per month
- 5–7.5 mg doses: approximately £160–£200 per month
- 10–15 mg doses (maximum): approximately £220–£320 per month
Each KwikPen contains four weekly injections (one month supply). Costs may be lower if you purchase multiple months upfront. Private access means you pay from the start but avoid NHS waiting lists — typically receiving your first prescription within 5–7 days of your online clinical assessment with a UK-licensed prescriber. Use our GLP-1 weight loss calculator to explore projected outcomes at different doses before committing.
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 for Mounjaro
NHS access: Mounjaro is available free through NHS specialist tier 3 weight management services, but access is limited by regional availability and waiting lists can extend 6–18 months in many areas. You'll need a GP referral and meet strict eligibility criteria (BMI ≥30 or BMI ≥27 with weight-related health conditions). Private access: Faster but costs money. You complete an online consultation with a UK-licensed prescriber, receive a prescription if approved, and collect your medication from a GPhC-registered pharmacy within days. No NHS referral needed. Most people choose private access for speed; some combine private initial treatment with later NHS continuation. Calculate your personal BMI using our free BMI calculator to check your eligibility threshold first.
- 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 cheaper through the NHS?
Yes — NHS prescriptions are free to eligible patients. However, NHS access involves waiting lists (often 6–18 months) and is only available through specialist tier 3 weight management services, not standard GP prescription. You need a referral and must meet strict criteria. Many people choose private access for speed despite the cost.
Why does Mounjaro cost different amounts privately?
Cost varies by dose and pharmacy. Starting dose (2.5 mg) is cheaper than maximum dose (15 mg). Some private providers offer discounts for multiple-month purchases or loyalty schemes. Prices typically range £129–£320 per month depending on your tirzepatide dose level.
What's included in the private Mounjaro cost?
Private costs cover the prescription fee, clinical assessment, and the medication itself (one KwikPen with four weekly injections). You don't pay for GP referral or NHS services when using private prescribing. Some providers may charge separately for follow-up consultations.
Can I get Mounjaro on prescription without paying?
Yes, through NHS tier 3 specialist weight management services if you meet eligibility criteria and are referred by your GP. This is free but involves waiting lists. Private prescribing costs but is faster — typically 5–7 days from consultation to delivery.
Is private Mounjaro legitimate in the UK?
Yes, if prescribed by a UK-licensed doctor and dispensed by a GPhC-registered pharmacy. Always verify the pharmacy is GPhC-registered and the prescriber is GMC-registered. Legitimate private providers require an online clinical assessment before issuing a prescription — never trust providers that skip this step.
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.