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 Can I Get Mounjaro On The NHS?
Mounjaro (tirzepatide) is available in the UK through both NHS and private routes, but access differs significantly. On the NHS, you'll typically need referral to a specialist weight management service, which involves waiting lists and regional variation. Privately, you can access Mounjaro through an online prescription following a clinical assessment. This guide explains both pathways, costs, and what to expect at each stage of the process.
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 — How The Referral Works
NHS access to Mounjaro is through tier 3 specialist weight management services, not your GP alone. You cannot simply ask your GP to prescribe Mounjaro — you must be referred to a specialist multidisciplinary weight management team, usually run by your local Integrated Care Board (ICB).
- Step 1: Your GP assesses your BMI and weight-related health conditions to determine if specialist referral is appropriate
- Step 2: You're referred to your local tier 3 weight management service
- Step 3: The specialist team conducts a full assessment and decides if tirzepatide is clinically suitable
- Step 4: If approved, they'll prescribe and manage your treatment
NICE has approved tirzepatide (Mounjaro) for use within NHS weight management services for adults with a BMI of 30 or above, or 27–29.9 with weight-related health conditions like type 2 diabetes, hypertension, or cardiovascular disease. Regional availability varies significantly — some ICBs have well-resourced services with reasonable waiting times; others have waiting lists extending months or years.
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 Mounjaro Access & Cost Comparison
Private access is faster and doesn't require NHS referral. You can get Mounjaro through a GPhC-registered online pharmacy following an online clinical assessment with a UK-licensed prescriber. Typical private costs range from approximately £150–£320 per month depending on your dose.
- No NHS waiting list — usually prescribed within 1–5 days
- Prescription issued if clinically appropriate following assessment
- Dispensed by a regulated pharmacy in the UK
- You manage your own dose escalation following the treatment protocol
Private treatment means you cover the full cost, but you avoid waiting lists entirely. Many people use private access when NHS waiting times are prohibitive, particularly those with significant weight-related health complications. Our GLP-1 weight loss calculator can help you estimate potential results and associated costs at different dose levels.
- 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 BMI do I need to qualify for Mounjaro on the NHS?
Adults with a BMI of 30 or above, or 27–29.9 with weight-related health conditions (type 2 diabetes, hypertension, cardiovascular disease, or sleep apnoea), may be eligible. For South Asian, Chinese, Black African, or Black Caribbean adults, lower BMI thresholds may apply. Your GP will assess your specific circumstances.
How long are NHS waiting lists for Mounjaro?
Waiting times vary significantly by region. Some areas have 2–4 month waits, whilst others exceed 12 months. Contact your local ICB or ask your GP for your regional waiting time estimate. Private access avoids waiting lists entirely.
Does the NHS cover Mounjaro on prescription once approved?
Yes, once prescribed through an NHS specialist weight management service, Mounjaro is provided at standard NHS prescription costs (£9.65 per item in England as of 2026, or free if you qualify for exemptions).
What happens during a private online clinical assessment for Mounjaro?
You'll answer questions about your weight, height, medical history, current medications, and weight-related health conditions. A UK-licensed prescriber reviews your answers and decides if tirzepatide is clinically appropriate. If approved, they issue a prescription, which a GPhC pharmacy dispenses to you.
Can I switch from private Mounjaro to NHS prescription?
Potentially, but it's complex. If you're already on private tirzepatide and later become eligible for NHS specialist services, discuss this with the NHS team. Some services may continue private treatment whilst you wait for NHS assessment, whilst others may require you to restart through the NHS pathway.
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.