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 Do I Get Mounjaro in the UK?
Getting Mounjaro (tirzepatide) in the UK involves two main routes: through the NHS via specialist weight management services, or privately through an online clinical assessment with a UK-licensed prescriber. Mounjaro is a prescription-only injectable medicine, so you'll need to be assessed to check if it's clinically appropriate for you. Your eligibility depends on your BMI and any weight-related health conditions. This guide explains both pathways and what happens next. Use our free GLP-1 weight loss calculator to explore potential results with Mounjaro at different doses.
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.
NHS Route vs Private Route — Which Path Is Right for You?
NHS Route: If you want Mounjaro on the NHS, you'll need to be referred to a tier 3 specialist weight management service by your GP. Your GP will assess your initial eligibility (BMI of 30 or above, or 27–29.9 with weight-related health conditions). If eligible, your GP can refer you to your local NHS weight management service. However, NHS access to Mounjaro varies significantly by region and waiting lists can be lengthy — sometimes months or even years in some areas. NHS NICE guidance has approved tirzepatide (Mounjaro's active ingredient) for weight management in eligible adults.
Private Route: Alternatively, you can access Mounjaro privately through a GPhC-registered online pharmacy following a consultation with a UK-licensed prescriber. This doesn't require an NHS referral and is typically faster. You'll complete an online health questionnaire, and a prescriber will assess whether Mounjaro is suitable based on your individual circumstances. If approved, your prescription is dispensed directly by the pharmacy. Private costs vary but typically range from £129–£320 per month depending on dose and provider.
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.
What Makes You Eligible for Mounjaro?
To be eligible for Mounjaro, you must be an adult (18 or over) with a BMI of 30 kg/m² or above, or a BMI of 27–29.9 kg/m² with at least one weight-related health condition. Weight-related conditions include type 2 diabetes, prediabetes, high blood pressure, abnormal cholesterol levels, sleep apnoea, or a history of heart disease or stroke. If you're of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds apply — your eligibility may begin at BMI 27.5 or above due to higher health risks at lower weights. You cannot take Mounjaro if you're under 18, pregnant, breastfeeding, or allergic to tirzepatide. Use our free BMI calculator to check your personal BMI against these eligibility criteria.
- 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.
How long does it take to get Mounjaro on the NHS?
Waiting times vary by region and NHS service availability. Some areas have waiting lists of several months to over a year. Your GP can tell you about typical waiting times in your local area. Private routes are usually faster — typically 1–2 weeks from consultation to first injection.
Do I need to see my GP first to get Mounjaro?
Yes, for the NHS route you must be referred by your GP to a specialist weight management service. For the private route, you don't need a GP referral — you can access a private online consultation directly with a licensed prescriber.
What's the difference between getting Mounjaro on the NHS vs privately?
NHS access is free but involves referral, assessment by specialists, and often longer waiting times. Private access is faster and doesn't require NHS referral, but you pay out of pocket. Both require clinical assessment to confirm Mounjaro is suitable for you.
Can I start Mounjaro immediately or does the dose gradually increase?
Mounjaro uses a gradual dose titration schedule. You start at 2.5 mg once weekly, then increase every 4 weeks (5 mg, 7.5 mg, 10 mg, 12.5 mg, and up to 15 mg maximum) based on how you respond and tolerate the medication.
Is Mounjaro the same as Wegovy?
No. Both are weight loss injections available in the UK, but they're different medications. Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist. Wegovy (semaglutide) is a GLP-1 agonist only. Both are prescription-only and require clinical assessment, but they work via slightly different mechanisms.
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.