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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Who Makes Mounjaro and How to Access It in the UK
Mounjaro (tirzepatide) is manufactured by Eli Lilly and Company, a major pharmaceutical manufacturer. It's a prescription-only weight management injection licensed in the UK, available through both NHS specialist services and private online prescribing routes. This guide explains who makes Mounjaro, how it's approved in the UK, how to access it, and what you can expect to pay depending on your chosen route.
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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.
Eli Lilly, Manufacturing, and UK Approval
Eli Lilly and Company is a global pharmaceutical manufacturer headquartered in Indianapolis, USA, with a significant UK presence. Mounjaro (tirzepatide) is manufactured under Eli Lilly's brand and is subject to MHRA (Medicines and Healthcare products Regulatory Agency) approval and ongoing monitoring in the UK. The medication carries a Black Triangle (▼) designation, meaning it is subject to additional monitoring for safety.
Mounjaro was approved by the MHRA for weight management in adults in 2023. NICE (National Institute for Health and Care Excellence) has since recommended tirzepatide as an option for weight management in specialist tier 3 and tier 4 NHS services, alongside other weight loss medications including Wegovy (semaglutide). The approval means Mounjaro meets UK standards for safety, quality, and efficacy—though it is still relatively new to the market compared to established weight loss options.
- Manufactured by Eli Lilly globally
- MHRA-approved and licensed in the UK
- NICE-recommended for NHS specialist services
- Available as a pre-filled KwikPen auto-injector
- Subject to additional safety monitoring (Black Triangle status)
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.
Accessing Mounjaro in the UK: NHS vs Private
NHS access: Mounjaro is available through specialist weight management services (tier 3 and tier 4). You'll need a GP referral, and availability varies significantly by region and local ICB (Integrated Care Board). Waiting lists can be lengthy—sometimes months to years depending on your area. Once referred, a specialist team assesses your eligibility, BMI, health conditions, and medication history before prescribing.
Private access: You can obtain a Mounjaro prescription privately through an online consultation with a UK-licensed prescriber. This route does not require an NHS referral. Following a clinical assessment, if Mounjaro is deemed suitable, a prescription is issued and dispensed by a GPhC-registered pharmacy. You pay the full cost privately. Private prices typically range from £129 to £320+ per month depending on your dose—starting doses cost less than higher maintenance doses. Your GP may be willing to monitor your health whilst using privately-sourced Mounjaro.
Use our free GLP-1 weight loss calculator to estimate potential weight loss outcomes at different Mounjaro doses. For quick comparisons between Mounjaro and similar options like Wegovy, our BMI calculator helps you understand your starting point and what weight loss percentage might mean for your health. Both tools are available above on this page.
- 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 in the UK?
Yes, Mounjaro (tirzepatide) is available through NHS specialist weight management services following NICE recommendation. Access requires a GP referral and assessment by a specialist team. Availability and waiting times vary significantly by region. Private access is also available without an NHS referral.
How much does Mounjaro cost privately in the UK?
Private Mounjaro costs typically range from £129 to £320+ per month depending on your dose. Starting doses (2.5 mg and 5 mg) cost less than higher maintenance doses (10 mg, 15 mg). Some providers offer package pricing for multiple months. Always check with the prescribing service for exact current costs.
What is a KwikPen and how does Mounjaro come supplied?
Mounjaro is supplied as a pre-filled KwikPen auto-injector device. Each pen contains one weekly dose and comes in a box of 4 pens (one month's supply). You simply dial the dose, insert the needle into the skin, and press the injection button. Pens are stored in a refrigerator before use.
How long does it take to get Mounjaro through the NHS?
NHS waiting times depend on your local area and tier 3/4 service capacity. Some regions have waiting lists of several months to over a year. Private routes are faster—you can typically get an appointment within days and a prescription within 1–2 weeks if approved.
Can my GP prescribe Mounjaro, or do I need a specialist?
In most cases, Mounjaro is prescribed through specialist weight management services (tier 3/4), not standard GP practice. However, some GPs may monitor your health if you're using privately-sourced Mounjaro. Always discuss with your GP about monitoring options regardless of your access route.
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.