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 Injection Price Comparison in the UK
Mounjaro (tirzepatide) is a prescription-only weekly weight loss injection available in the UK through both NHS specialist services and private online prescribing routes. Costs vary significantly depending on whether you access the medication through the NHS or privately, and the specific dose you're prescribed. Understanding your options helps you make an informed decision about whether this medication is right for your weight management journey and budget.
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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 Costs in the UK
Private prescription costs for Mounjaro typically range from £129 to £320 per month, depending on your dose and the provider. The starting dose (2.5 mg) is usually at the lower end of this range, while higher maintenance doses (10 mg to 15 mg) cost more. Each KwikPen contains 4 weekly doses, so monthly costs reflect a full four-week supply. Private prescribing involves an online consultation with a UK-licensed prescriber, who will assess your eligibility before issuing a prescription. If approved, your prescription is dispensed by a GPhC-registered pharmacy. You can use our GLP-1 weight loss calculator above to estimate potential outcomes at different doses, helping you understand what investment might support your goals.
- Starting dose (2.5 mg): approximately £129–£160/month
- Mid-range doses (5–10 mg): approximately £180–£250/month
- Maximum dose (15 mg): approximately £280–£320/month
- No NHS referral required for private access
- Results typically visible within 4–8 weeks at maintenance dose
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 Access vs Private Routes
NHS access to Mounjaro is free at point of use but requires referral to a specialist tier 3 weight management service through your GP. NICE has approved tirzepatide for NHS use, however availability and waiting times vary significantly by region and Integrated Care Board (ICB). Some areas have waiting lists exceeding 12 months, whilst others may offer faster access. Private prescribing bypasses NHS waiting lists entirely—you can start a consultation within days and receive your first prescription within 1–2 weeks if clinically appropriate. The online consultation process involves completing a health questionnaire, discussing your medical history with a prescriber, and receiving a decision on suitability. Both routes require a genuine clinical assessment; neither offers medication without proper evaluation of your health status and eligibility.
When comparing cost and access, consider not just the monthly fee but also your waiting time tolerance and preference for ongoing support. NHS services offer multidisciplinary support including dietitian guidance and psychological support, though with longer waits. Private routes offer faster access and flexibility but require you to self-fund. Using our free BMI calculator can confirm whether you meet eligibility criteria (BMI 30+ or BMI 27+ with weight-related health conditions), helping you decide whether to pursue either route. Some people use private access initially, then transition to NHS prescribing once available in their region.
- 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.
How much does Mounjaro cost on the NHS?
Mounjaro is free on the NHS when prescribed through a specialist tier 3 weight management service, but access requires GP referral and specialist assessment. Availability and waiting times vary significantly by region—some areas have waiting lists of 6–18 months.
Can I get Mounjaro privately without NHS referral?
Yes. Private online prescribing is available through GPhC-registered pharmacies following a consultation with a UK-licensed prescriber. This bypasses NHS referral requirements but requires self-funding at approximately £129–£320 per month depending on dose.
What's included in private Mounjaro costs?
Private costs cover the prescription fee, clinical assessment, and the medication itself (one KwikPen = 4 weekly doses). Ongoing GP monitoring may incur additional fees depending on your chosen provider, so always confirm what's included before starting.
Is Mounjaro cheaper than Wegovy in the UK?
Costs are broadly similar—both typically range £129–£320/month privately depending on dose. Mounjaro's dual GIP/GLP-1 mechanism may produce different results than Wegovy's single GLP-1 action, so choice should be based on clinical suitability and prescriber recommendation, not cost alone.
How do I check if I'm eligible for Mounjaro before paying?
You meet basic eligibility if your BMI is 30+ (or 27+ with weight-related health conditions like type 2 diabetes, hypertension, or sleep apnoea). Use our free BMI calculator above to check your BMI, then discuss with your GP or a private prescriber about suitability for this weekly weight loss injection.
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.