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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How Much Is Mounjaro in the UK?
Mounjaro (tirzepatide) costs vary significantly depending on how you access it in the UK. Through the NHS, it may be available free if prescribed by a specialist weight management service, though eligibility and availability depend on your local area. Via private prescription, Mounjaro typically costs between £129 and £300 per month, depending on your dose and the provider. Understanding both routes—NHS and private—helps you make an informed decision about access and affordability. Your GP can advise on what's available in your region.
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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.
Mounjaro Cost on Private Prescription in the UK
Private prescription costs for Mounjaro in the UK typically range from £129 to £300 per month, with price varying by dose strength and provider. A single KwikPen contains 4 weekly doses (a 4-week supply), so monthly costs reflect this one-pen supply. Lower doses (2.5 mg and 5 mg) are generally less expensive than higher doses (10 mg, 15 mg). Most private providers offer transparent pricing, and you can compare costs across GPhC-registered online pharmacies before committing. Some pharmacies offer package discounts if purchasing multiple months upfront. It's essential to note that private prescription costs are separate from any consultation fees charged by the prescriber—typically £20 to £50 for an initial online assessment. These are one-off charges, not monthly.
- Starting doses (2.5–5 mg): typically £129–£180 per month
- Mid-range doses (7.5–10 mg): typically £180–£240 per month
- Higher doses (12.5–15 mg): typically £240–£300 per month
- Always check the full price including prescription fee before ordering
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 Prescription Route
Access to Mounjaro through the NHS is available for eligible adults through specialist tier 3/4 weight management services, typically at no cost if prescribed. However, NHS access requires referral from your GP and assessment by a specialist team—waiting lists can be several months to over a year depending on your area. NICE (National Institute for Health and Care Excellence) has approved tirzepatide (Mounjaro) for NHS use, but availability varies significantly by integrated care board (ICB). Private prescription offers faster access—you can start within days of a successful online clinical assessment—but at personal cost. The private route does not require an NHS referral or GP involvement. Both routes require a prescription from a UK-licensed prescriber and a clinical assessment to confirm the medication is appropriate 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.
How do I get Mounjaro on the NHS in the UK?
Ask your GP for a referral to your local tier 3 specialist weight management service. NICE has approved Mounjaro for NHS prescription, but you must meet eligibility criteria (BMI ≥30 or ≥27 with weight-related health conditions) and be assessed by the specialist team. Availability and waiting times vary by region. Your GP can tell you what's available in your area.
How quickly can I access Mounjaro privately?
Private access is typically much faster. After booking an online consultation with a UK-licensed prescriber (usually within days), you'll have an assessment and, if approved, a prescription within 24–48 hours. Your first KwikPen can be dispensed and delivered within days. Total time from booking to receiving your first dose: often 1–2 weeks.
Do I need a prescription for Mounjaro in the UK?
Yes, absolutely. Mounjaro is prescription-only in the UK. You cannot buy it over-the-counter. Whether accessing via NHS or privately, you must have a prescription from a UK-registered prescriber and a valid clinical assessment showing the medication is appropriate and safe for you.
Can I switch from NHS Mounjaro to private prescription?
Yes, you can. If you're on an NHS waiting list and want faster access, you can pursue private prescription independently. However, inform your GP of any private prescription you start, as your medical records should reflect all medications you're taking. Never overlap prescriptions from both NHS and private sources.
What factors affect Mounjaro cost in the UK?
Private costs depend on your dose (higher doses cost more), your provider, and whether you buy single doses or multi-month packages. Initial consultation fees (£20–£50) are separate from medication costs. NHS prescriptions are free but involve waiting times. Your local NHS area and whether you're eligible for specialist services also affect access speed and cost.
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.