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 to Access and Compare Mounjaro in the UK
If you're considering Mounjaro (tirzepatide) for weight management in the UK, understanding how to access it and what it costs is essential. Mounjaro is a prescription-only GLP-1 receptor agonist available through both NHS specialist services and private online prescribing routes. This guide explains your options, eligibility criteria, costs, and what to expect from the application and prescription process in the UK.
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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.
UK Cost and Access Routes for Mounjaro
Mounjaro is available through two main routes in the UK: NHS specialist tier 3 weight management services and private prescription routes. NHS access requires referral from your GP to a specialist weight management service, though availability and waiting times vary significantly by region and ICB (Integrated Care Board). Many areas have substantial waiting lists, sometimes months or even years. Private access involves an online consultation with a UK-licensed prescriber, typically available within days if you meet eligibility criteria. Private costs range from approximately £129–£320 per month depending on your dose, supply duration, and provider. Each Mounjaro KwikPen contains four weekly injections (one month's supply). When comparing different routes, factor in consultation fees, delivery times, ongoing support, and whether your GP will monitor your progress.
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 vs Private: What to Expect
The NHS route involves assessment by a specialist multidisciplinary team, free prescription costs once approved, and regular NHS monitoring. However, eligibility is often limited to those with BMI ≥30 or BMI 27–29.9 with weight-related health conditions, and access depends on local commissioning decisions. The private route offers faster access without NHS referral. An online consultation assesses your medical history, BMI, and eligibility. If approved, a prescription is issued to a GPhC-registered pharmacy. You'll need to arrange private monitoring with your prescriber. Use our free BMI calculator above to check your personal BMI and understand your eligibility starting point. The tirzepatide uk prescription process is straightforward: complete your health questionnaire, have your assessment, receive your prescription, and begin your Mounjaro KwikPen injections within days.
- 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.
What is the typical cost of Mounjaro per month in the UK?
Private prescription costs typically range from £129–£320 per month, depending on your maintenance dose (5mg, 10mg, or 15mg) and the supply duration you choose. Starting doses (2.5mg) may be cheaper. NHS prescription is free once approved, but accessing NHS treatment involves waiting for referral and specialist assessment. Always confirm current pricing with your provider as costs can vary.
How long does it take to get Mounjaro on the NHS?
NHS waiting times vary significantly by region. Many areas have waiting lists of several months to over a year for specialist weight management services. Private prescription typically takes 1–3 days from online consultation to receiving your medication. Check with your local ICB for specific NHS timescales in your area.
Do I need a referral from my GP to access Mounjaro privately?
No. Private online prescribing does not require a GP referral. You complete an online health questionnaire, have an assessment with a UK-licensed prescriber, and if approved, receive a prescription from a GPhC-registered pharmacy. However, it's good practice to inform your GP that you're taking Mounjaro so they can monitor your progress.
What happens after I'm prescribed Mounjaro — how do I get my injections?
Once prescribed, your KwikPen pens are delivered to your home address. Each pen contains four weekly doses. You store them in the fridge and inject yourself once weekly, rotating injection sites. Many private providers offer ongoing support via phone or messaging to monitor your progress and manage any side effects.
Is Mounjaro more expensive than Wegovy in the UK?
Costs are broadly similar, typically £129–£320 per month depending on dose. Mounjaro (tirzepatide) and Wegovy (semaglutide) have comparable pricing structures on the private market. Exact costs vary by provider and dose. NHS costs are identical (free) for both if you access them through NHS services, though availability differs by region.
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.