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 Cost in the UK — Your Options Explained
Finding affordable Mounjaro (tirzepatide) in the UK depends on whether you access it through the NHS or privately. Mounjaro is a prescription-only weekly weight loss injection that costs significantly less through NHS specialist services if you're eligible, but private access offers faster alternatives. Understanding both routes helps you make an informed decision about this GLP-1 and GIP receptor agonist medication and what it might cost you.
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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 to Mounjaro — Cost and Eligibility
Mounjaro through the NHS is typically free when prescribed by a tier 3 specialist weight management service, though availability varies significantly by region. You'll need a GP referral to access NHS specialist services, and eligibility criteria include a BMI of 30 or above, or BMI of 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or obstructive sleep apnoea.
NICE (the National Institute for Health and Care Excellence) has approved tirzepatide for use within NHS specialist weight management services, recognising its role alongside reduced-calorie diet and increased physical activity. However, waiting lists for tier 3 services can be lengthy — often months to over a year in many areas. If you're eligible, your GP can refer you, and a prescriber will assess whether Mounjaro is appropriate for you based on your individual health profile and medical history.
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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 — Cost, Speed, and Accessibility
Private Mounjaro prescriptions in the UK cost approximately £129–£320 per month depending on your dose and the prescribing provider. A starting dose (2.5 mg) costs less than the maximum dose (15 mg). Private prescribing offers faster access without NHS waiting lists — you can receive a prescription within days following an online clinical assessment with a UK-licensed prescriber through a GPhC-registered pharmacy.
This route requires no GP referral and is available regardless of NHS tier 3 service availability in your area. However, you pay privately each month. Some people use our GLP-1 weight loss calculator to estimate potential outcomes at different doses before committing to treatment costs.
NHS Waiting Lists vs Private SpeedThe critical difference between routes is wait time and certainty. NHS access is free but can involve waiting months for a tier 3 appointment, then further waiting for assessment and prescription initiation. Private access costs money but typically delivers a prescription within 2–7 days. For those in areas with very limited NHS specialist services, or for whom timeliness is important, private prescribing offers certainty at a known cost.
Your GP can advise which route suits your circumstances. Use our BMI calculator above to check your starting point, and discuss both NHS and private options with your healthcare provider to find the most affordable and accessible route 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?
Yes, Mounjaro is free on the NHS when prescribed through a tier 3 specialist weight management service, but you must be eligible (BMI ≥30, or ≥27.9 with weight-related health conditions) and referred by your GP. Waiting times vary significantly by region — often several months to over a year.
How much does Mounjaro cost privately in the UK?
Private Mounjaro costs approximately £129–£320 per month depending on your dose. A 2.5 mg starting dose is cheaper than the 15 mg maximum dose. This includes the prescription and medicine dispensed by a GPhC-registered pharmacy following an online clinical assessment.
What's the difference between NHS and private Mounjaro access?
NHS access is free but involves GP referral, tier 3 assessment, and waiting lists (often months). Private access costs £129–£320/month but offers a prescription within days without referral. Both require a UK-licensed prescriber's assessment.
Can I switch from private to NHS Mounjaro?
Potentially, yes. If you start privately and later become eligible for NHS access, you could ask your GP about referral to a tier 3 service. However, this requires assessment and may involve restarting treatment. Discuss continuity with your prescriber before switching.
What's included in the private Mounjaro cost?
The private cost (£129–£320/month) includes the prescription fee, the tirzepatide medication itself, and delivery. This is a complete monthly cost. Some providers may offer dose-specific pricing — clarify exact costs before starting treatment.
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.