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 Expensive Is Mounjaro in the UK?
Mounjaro (tirzepatide) costs vary significantly depending on whether you access it through the NHS or privately in the UK. Private prescription costs typically range from £129 to £320 per month, depending on your dose and provider. NHS access is free but available only through specialist tier 3 weight management services and subject to regional availability. Understanding the cost and eligibility criteria can help you make an informed decision about whether this prescription-only medication is right for you. Use our free BMI calculator above to check if you may be eligible for weight loss 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.
Mounjaro Costs: NHS vs Private Access in the UK
NHS access: Mounjaro prescribed through the NHS is completely free at point of care if you meet eligibility criteria. However, NHS availability is extremely limited. Access is through tier 3 specialist weight management services (not standard GP prescription), and you must be referred by your GP. Most regions have significant waiting lists—some extending months or even years. NICE has approved tirzepatide for NHS use, but regional ICBs (Integrated Care Boards) control funding and availability, so access varies dramatically across the UK.
Private access: Through GPhC-registered online pharmacies following a clinical assessment, Mounjaro costs vary by dose and provider. A Mounjaro KwikPen (4 weeks supply, single dose) typically costs: Starting doses (2.5mg): £129–£150. Maintenance doses (5mg–7.5mg): £179–£220. Higher doses (10mg–15mg): £250–£320. These prices may include the consultation fee or it may be charged separately (typically £20–£50). Prices fluctuate, so always confirm current costs directly with your chosen provider.
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.
Why Mounjaro Costs Vary and How to Access It
Cost variation reflects dose escalation—you begin on a lower dose and increase gradually each month, so your first month costs less than later months. Private pricing also reflects individual provider margins and consultation fees. Many people find private access more affordable than waiting months for NHS availability, though cost remains a barrier for some. To explore whether Mounjaro is suitable for you, use our free GLP-1 weight loss calculator to estimate potential results, then discuss eligibility and costs with a prescriber. You may also want to compare alternatives like Wegovy (semaglutide), which has similar pricing but different dosing schedules.
- 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 available on the NHS for weight loss?
Yes, NICE has approved tirzepatide (Mounjaro) for NHS weight management services. However, access is extremely limited and restricted to tier 3 specialist weight management services. You must be referred by your GP and meet eligibility criteria (BMI ≥30, or ≥27 with weight-related health conditions). Regional availability varies significantly—some areas have long waiting lists or no current availability. Contact your local weight management service or ask your GP about tier 3 referral options in your region.
How much does a Mounjaro KwikPen cost privately in the UK?
Mounjaro KwikPens cost £129–£320 per month privately in the UK, depending on your dose and provider. Starting doses (2.5mg) cost around £129–£150. Maintenance doses (5mg–10mg) cost £179–£250. Maximum dose (15mg) costs approximately £250–£320. Prices may include or exclude the clinical consultation fee (typically £20–£50 extra). Always confirm current pricing with your chosen GPhC-registered pharmacy, as prices do fluctuate.
What is tirzepatide and how does it differ from Wegovy?
Tirzepatide is the active ingredient in Mounjaro. It's a dual GIP and GLP-1 receptor agonist—meaning it activates two natural hormone pathways to help reduce appetite and support weight loss. Wegovy (semaglutide) is a single GLP-1 agonist. Clinical trials show Mounjaro may produce slightly greater average weight loss (~15–21% body weight) compared to Wegovy (~15% body weight), though results vary between individuals. Both are prescription-only and have similar private costs in the UK.
Do I need to pay for Mounjaro consultations separately on the NHS?
No, Mounjaro consultations and prescriptions through the NHS are completely free if accessed through tier 3 specialist weight management services. However, availability is limited and you may wait several months for an appointment. Private online consultations typically cost £20–£50 extra on top of the medication cost, though some providers include this in their quoted price. Always clarify whether the consultation fee is included before committing to private treatment.
Can I get Mounjaro without a prescription in the UK?
No. Mounjaro is a prescription-only medicine in the UK—you cannot buy it without a valid prescription from a UK-licensed prescriber. You must either be referred to an NHS tier 3 weight management service (free but limited availability) or have a private online clinical assessment with a GPhC-registered pharmacy. The prescriber will assess your eligibility based on your BMI, health conditions, and medical history before issuing a prescription.
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.