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 Anyone Get Mounjaro in the UK?
No, not everyone can get Mounjaro in the UK — eligibility depends on your BMI, health conditions, and which route you choose to access it. Mounjaro (tirzepatide) is a prescription-only weight management injection available through both NHS specialist services and private online prescribing. Your GP or a licensed prescriber will assess whether this medication is suitable for you based on your individual health profile and weight-related risk factors.
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.
UK Mounjaro Eligibility Criteria and Access Routes
To be eligible for Mounjaro in the UK, you must be an adult aged 18 or over and meet one of these criteria:
- BMI of 30 kg/m² or above (obesity), OR
- BMI of 27–29.9 kg/m² with at least one weight-related health condition such as type 2 diabetes, prediabetes, high blood pressure, abnormal blood fats, obstructive sleep apnoea, or history of cardiovascular disease
If you're of South Asian, Chinese, Black African, or Black Caribbean heritage, lower BMI thresholds may apply — starting from BMI 27.5 or above. You cannot take Mounjaro if you're pregnant, breastfeeding, or have a severe allergy to tirzepatide. The NHS KwikPen device is the standard delivery method. Use our free BMI calculator above to check if you fall within the eligible range, though a prescriber must confirm suitability following a clinical assessment.
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.
NHS vs Private Mounjaro Access in the UK
NHS access: Available through tier 3 specialist weight management services following GP referral. NICE has approved Mounjaro use within NHS services, but availability and waiting times vary significantly by region — some areas have waits of 6–18 months. You will not be prescribed Mounjaro by your GP alone; you must be referred to a specialist centre.
Private access: Available through GPhC-registered online pharmacies and prescribing services. After an online clinical consultation with a UK-licensed prescriber, a prescription is issued if clinically appropriate. Costs typically range from £130–£320 per month depending on dose. Try our GLP-1 weight loss calculator to project potential outcomes and understand whether this option is right for you.
The online private prescription process is straightforward: complete a health questionnaire, have a brief consultation with a prescriber, receive your prescription, and your medication is dispatched by a registered pharmacy. Unlike the Mounjaro vs Wegovy comparison where mechanisms differ, both GLP-1 medications have similar eligibility criteria in the UK. Doses start at 2.5 mg weekly, titrating up over 16+ weeks to a maximum of 15 mg. Your prescriber will guide dose escalation based on your response and side effects. Mounjaro side effects UK commonly include nausea and constipation, typically mild and resolving over time.
- 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 be eligible for Mounjaro in the UK?
You need a BMI of 30 or above, or 27–29.9 if you have weight-related health conditions like diabetes or high blood pressure. For South Asian, Chinese, Black African, or Black Caribbean adults, lower thresholds apply. Use our BMI calculator above to check your personal BMI and health context.
How much does Mounjaro cost privately in the UK?
Private Mounjaro costs typically range from £130–£320 per month depending on your dose. Prices vary slightly between providers. NHS access is free but has significant waiting lists in many regions. Compare costs across registered online prescribing services before deciding.
Can I get Mounjaro on the NHS?
Yes, Mounjaro is approved by NICE for NHS specialist weight management services. Access is through tier 3 services following GP referral, not standard GP prescription. Waiting times vary from weeks to 18+ months depending on your region and local service capacity.
What's the difference between Mounjaro eligibility and Wegovy eligibility?
Both Mounjaro and Wegovy have the same BMI and health condition eligibility criteria in the UK. The main difference is mechanism — Mounjaro is a dual GIP/GLP-1 agonist while Wegovy is GLP-1 only. Your prescriber will assess which is more suitable based on your individual health profile.
Do I need a prescription from my GP to get private Mounjaro?
No. For private prescriptions, you consult directly with a UK-licensed prescriber through an online service. They assess your suitability, issue a prescription if appropriate, and a GPhC-registered pharmacy dispenses it. You don't need a GP referral for private access.
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.