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
What Is Mounjaro's Generic Name and How to Access It in the UK?
Mounjaro's generic name is tirzepatide, a dual GIP and GLP-1 receptor agonist injection for weight management. In the UK, Mounjaro is available through NHS specialist weight management services or private online prescribing. Understanding the generic name—tirzepatide—helps when researching the medication, comparing treatment options, and discussing it with your GP. This guide explains how to access Mounjaro in the UK, what it costs, and the eligibility requirements you'll need to meet.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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.
Understanding Tirzepatide (Mounjaro) and UK Access Routes
Tirzepatide is the generic name for Mounjaro, manufactured by Eli Lilly. It's a once-weekly injectable medication available in the UK as a prescription-only medicine. The medication comes as a pre-filled KwikPen device and is licensed for weight management in adults with a BMI of 30 or above, or 27–29.9 with weight-related health conditions.
In the UK, you can access tirzepatide (Mounjaro) through two main routes:
- NHS route: Referral to a tier 3 specialist weight management service through your GP. Access varies significantly by region and waiting times can be lengthy.
- Private route: Online consultation with a UK-licensed prescriber followed by dispensing through a GPhC-registered pharmacy. This typically takes days rather than months.
Both routes require a clinical assessment before prescription. Your prescriber will review your BMI, medical history, and weight-related conditions to confirm eligibility.
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.
UK Private Prescription Costs and NHS vs Private Access
Private prescription costs for tirzepatide (Mounjaro) in the UK typically range from £129 to £320 per month, depending on the dose you're prescribed. Starting doses (2.5 mg and 5 mg) are generally cheaper than maintenance or higher doses (10 mg, 15 mg). Costs may vary between private providers.
The NHS route is free at point of use but involves referral, specialist assessment, and often significant waiting lists. Private online prescribing offers faster access without NHS referral. Use our free GLP-1 weight loss calculator to explore potential outcomes at different doses, and our BMI calculator to check your current BMI and eligibility criteria before contacting a prescriber.
- 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 tirzepatide, the generic name for Mounjaro?
Tirzepatide is a dual GIP and GLP-1 receptor agonist—a prescription-only injectable medication licensed in the UK for weight management. It's marketed under the brand name Mounjaro and comes as a once-weekly injection in a pre-filled KwikPen.
How much does Mounjaro (tirzepatide) cost privately in the UK?
Private prescription costs for Mounjaro typically range from £129 to £320 per month depending on your dose. Starting doses are generally cheaper than higher maintenance doses. Prices may vary between different private prescribing providers.
Can I get tirzepatide (Mounjaro) on the NHS in the UK?
Yes, tirzepatide is available through NHS specialist tier 3 weight management services. You'll need a GP referral and clinical assessment. However, availability and waiting times vary significantly by region across the UK.
What are the UK eligibility requirements for Mounjaro?
Adults with a BMI of 30 or above, or 27–29.9 with weight-related health conditions (such as type 2 diabetes, hypertension, or sleep apnoea) may be eligible. South Asian, Chinese, Black African, and Black Caribbean adults may qualify at lower BMI thresholds due to higher health risks.
Is Mounjaro (tirzepatide) available without a prescription in the UK?
No, tirzepatide (Mounjaro) is prescription-only in the UK. You cannot purchase it without a prescription from a UK-licensed prescriber. A clinical assessment is always required before prescription to confirm eligibility and suitability.
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.