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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Understanding Monjaro Costs in the UK
If you're looking for affordable Monjaro (tirzepatide) in the UK, you have two main routes: NHS specialist services or private prescribing. NHS access is free at point of use but involves waiting lists and regional variation. Private Monjaro costs typically range from £129–£320 per month depending on dose and provider, making it a significant but potentially more accessible option for many people. This guide explains both pathways, eligibility criteria, and how to find affordable options that suit your circumstances.
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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 vs Private Routes for Monjaro
NHS route: Mounjaro is available through NHS specialist tier 3 weight management services, making it free at point of use — the most affordable option if you can access it. However, availability varies significantly by region and ICB (Integrated Care Board). Many areas have substantial waiting lists (sometimes 6 months to 2+ years). You'll need a GP referral and must meet strict eligibility criteria: BMI ≥30, or BMI 27–29.9 with weight-related health conditions like type 2 diabetes, hypertension, or sleep apnoea. Lower BMI thresholds (from 27.5) may apply if you're of South Asian, Chinese, Black African, or Black Caribbean heritage.
Private route: Private Monjaro prescribing through GPhC-registered online pharmacies costs approximately £129–£320 per month (depending on dose). You don't need a GP referral — simply complete an online clinical assessment with a UK-licensed prescriber. If approved, your prescription is dispensed within days. Private access is faster and bypasses NHS waiting lists, though it's not free. Some people view this as better value than waiting months for NHS services.
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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.
Making Monjaro More Affordable
To reduce the overall cost of Monjaro treatment: start at the lowest dose (2.5 mg per week) and only escalate every 4 weeks if needed — lower doses cost less and many people see meaningful results without reaching the maximum 15 mg dose. Ask about treatment duration — some people use Monjaro for 6–12 months to reach a target weight, then stop, rather than continuing indefinitely. Check if your private provider offers bulk discounts for longer prescriptions. Use our GLP-1 weight loss calculator above to estimate realistic outcomes at different doses, helping you decide the most cost-effective approach for your needs. Some private providers also offer loyalty pricing after the first few months.
- 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 Monjaro free on the NHS in the UK?
Monjaro is available free through NHS specialist tier 3 weight management services if you meet eligibility criteria and can access the service. However, availability varies greatly by region, and waiting lists are often 6–24 months. You need a GP referral and must have a BMI ≥30 (or ≥27 with weight-related health conditions). Contact your local weight management service for current waiting times.
How much does Monjaro cost privately in the UK?
Private Monjaro typically costs £129–£320 per month depending on the dose. Starting doses (2.5–5 mg) are cheaper; higher doses (10–15 mg) cost more. Costs are per weekly injection and don't include consultation fees (usually £30–£80 per assessment). Total monthly cost is roughly 4 weeks' supply plus any consultation charges.
What's the difference between tirzepatide and semaglutide cost-wise?
Monjaro (tirzepatide) and Wegovy (semaglutide) have similar private pricing, typically £129–£320/month depending on dose. Tirzepatide has a dual GIP and GLP-1 mechanism, potentially offering slightly greater average weight loss in clinical trials. Cost differences between the two are usually minimal — choice depends more on medical suitability and individual response.
Can I get Monjaro faster through private prescribing?
Yes. Private prescribing through online pharmacies is much faster — typically you can complete a consultation, receive a prescription, and have Monjaro dispensed within 3–7 days. NHS specialist services often involve months of waiting. Private is the faster route if you want to start treatment quickly, though it does involve out-of-pocket costs.
How do I check if I'm eligible for NHS Monjaro?
You're eligible if you have a BMI ≥30 kg/m², or BMI 27–29.9 with weight-related conditions (type 2 diabetes, hypertension, sleep apnoea, cardiovascular disease, or dyslipidaemia). Lower thresholds apply for South Asian, Chinese, Black African, or Black Caribbean adults. Use our free BMI calculator above to check your BMI, then speak with your GP about referral to specialist services.
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.