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
Can I Get Mounjaro Online in the UK?
Yes, you can access Mounjaro online in the UK, but availability depends on whether you pursue NHS or private routes. Mounjaro (tirzepatide) is a prescription-only weight management injection licensed by the MHRA for UK adults. NHS access is through specialist tier 3 weight management services, which typically involve waiting lists and regional variation. Private online prescribing offers faster access following a clinical assessment with a UK-licensed prescriber. Either route requires eligibility assessment based on your BMI and health conditions. Use our free BMI calculator above to check where your weight sits relative to NHS thresholds, then explore which route suits your circumstances.
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 Access to Mounjaro — Eligibility and Timeline
NHS access to Mounjaro is available through tier 3 specialist weight management services, not through standard GP prescriptions. You typically need a GP referral to access these services, though availability varies significantly by region and NHS integrated care board (ICB). NICE has approved tirzepatide for NHS use in specialist weight management, but many areas have substantial waiting lists — sometimes 12–24 months or longer.
To be eligible for NHS Mounjaro, you usually need:
- BMI of 30 kg/m² or above, OR
- BMI of 27–29.9 kg/m² with weight-related health conditions (type 2 diabetes, prediabetes, high blood pressure, sleep apnoea, or cardiovascular disease)
- For South Asian, Chinese, Black African, or Black Caribbean adults: lower thresholds may apply (BMI 27.5+)
Once referred, a specialist team assesses your suitability, reviews your weight management history, and discusses whether Mounjaro aligns with your goals. If approved, you receive a Mounjaro KwikPen prescription and ongoing clinic support. The dose titration process (starting at 2.5 mg and escalating weekly) is managed by the specialist team.
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 Online Access — Faster Route Without NHS Wait
Private online prescribing offers faster access to Mounjaro without NHS referral or waiting lists. You can request a consultation with a UK-licensed prescriber through a GPhC-registered online pharmacy. The prescriber reviews your medical history, BMI, and health conditions — similar eligibility criteria apply, but assessment is faster (usually within 24–48 hours).
If approved, you receive a prescription, and Mounjaro is dispensed by the registered pharmacy. Costs vary by dose: starter packs typically cost £129–£180 per month, escalation packs £200–£280 per month, and maintenance doses at 15 mg can reach £300–£320 per month. You manage your own dose escalation following guidance provided, though many private prescribers offer optional follow-up consultations. Try our free GLP-1 weight loss calculator to project potential outcomes at different Mounjaro doses, helping you weigh the investment against expected results.
- 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's the difference between NHS and private Mounjaro access in the UK?
NHS access is through specialist tier 3 services with a GP referral, free prescription, and professional support — but involves waiting lists. Private access is faster (24–48 hours) and doesn't require NHS referral, but costs £129–£320 monthly depending on dose. Both require clinical assessment and prescription.
How long is the NHS waiting list for Mounjaro?
NHS waiting times vary significantly by region (ICB). Some areas have 6–12 month waits, others 18–24 months or longer. Check with your local NHS weight management service for current timelines in your area. Your GP can refer you and provide an estimated wait when you're referred.
Can my GP prescribe Mounjaro directly?
No. Mounjaro is not a standard GP prescription. NHS access requires referral to a tier 3 specialist weight management service, where a consultant assesses your eligibility and manages your treatment. Private access requires an online consultation with a licensed prescriber through a regulated pharmacy.
What happens if I'm not eligible for NHS Mounjaro?
If your BMI or health conditions don't meet NHS criteria, private online prescribing may still be an option — prescriber eligibility can differ slightly. You could also pursue lifestyle changes (reduced-calorie diet, increased activity) via NHS Tier 1 or Tier 2 services, which are more accessible, or consult your GP about alternative weight management options suited to your circumstances.
Is private Mounjaro prescription safe if ordered online?
Yes, provided you use a GPhC-registered pharmacy and a UK-licensed prescriber. The prescriber reviews your medical history, performs a clinical assessment, and issues a prescription only if appropriate. Always verify the pharmacy's GPhC registration and the prescriber's credentials before proceeding. Your GP can also advise if online prescribing is suitable for you.
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.