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 Much Does Mounjaro Cost in the UK?
Mounjaro (tirzepatide) costs vary significantly depending on whether you access it through the NHS or privately in the UK. NHS access is free at the point of care but involves waiting for specialist services, whilst private prescriptions typically range from £150–£350 per month depending on your dose. Understanding both routes helps you make an informed decision about weight management options available to 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 and Eligibility for Mounjaro
NHS access to Mounjaro is free but not widely available yet. NICE (National Institute for Health and Care Excellence) has approved tirzepatide for use within NHS specialist weight management services, though regional rollout is ongoing. Eligibility requires referral to a tier 3 or tier 4 specialist weight management service — you cannot obtain Mounjaro from your GP without this referral.
Eligibility criteria:
- BMI of 30 kg/m² or above, OR
- BMI of 27–29.9 kg/m² with weight-related health conditions (type 2 diabetes, hypertension, cardiovascular disease, sleep apnoea)
- For South Asian, Chinese, Black African, and Black Caribbean adults, lower thresholds apply (BMI 27.5+)
NHS waiting lists for specialist services vary dramatically by region — some areas have waiting times of 12–24 months or longer. Contact your local integrated care board (ICB) to check current availability in your area. Calculate your personal eligibility using our free BMI calculator above to understand whether you meet the criteria.
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.
Private Mounjaro Costs and Access in the UK
Private Mounjaro costs range from approximately £150–£350 per month, depending on your dose and the provider. Pricing is typically per dose or per month's supply. A full starter pack (four KwikPens at 2.5 mg) costs around £150–£180, whilst maintenance doses (5–15 mg) cost £200–£350 monthly. Private access does not require NHS referral — you book an online consultation with a UK-licensed prescriber, who assesses your eligibility and issues a prescription if appropriate. This route is faster than NHS waiting lists but requires upfront payment. Many people use our GLP-1 weight loss calculator to compare estimated outcomes at different doses before committing to private treatment.
- 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 if prescribed through a specialist tier 3 or tier 4 weight management service. However, you must be referred by your GP and meet NICE eligibility criteria (BMI 30+ or BMI 27+ with weight-related conditions). Availability varies by region, and waiting lists are typically long. Private prescriptions are not free and cost £150–£350 monthly.
How long is the NHS waiting list for Mounjaro?
NHS waiting times vary significantly by region. Some areas have waits of 6–12 months, whilst others exceed 24 months. Contact your local integrated care board (ICB) to check current waiting times in your area. Private online prescribing is much faster — typically assessed and prescribed within 1–7 days if you meet clinical criteria.
What is the difference between Mounjaro and Wegovy?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist, whilst Wegovy (semaglutide) is a GLP-1 agonist only. Clinical trials show Mounjaro may achieve slightly higher average weight loss (~20% vs ~15% body weight), though individual results vary. Both are prescription-only and available through NHS specialist services or privately in the UK.
Can I get Mounjaro without waiting on the NHS?
Yes. Private online prescribing bypasses NHS waiting lists — you can access a UK-licensed prescriber, have a clinical assessment, and receive a prescription typically within days if you meet eligibility criteria. You then collect your prescription from a GPhC-registered pharmacy. This route requires payment (around £150–£350 monthly) but is faster than NHS routes.
Does my dose of Mounjaro affect the cost?
Yes, private costs increase with dose. The starter dose (2.5 mg) costs around £150–£180 per month, whilst higher doses (10–15 mg) cost £250–£350 monthly. Most people start at 2.5 mg and increase by 2.5 mg every four weeks until reaching their maintenance dose, spreading costs over several months as they titrate upwards.
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.