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
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How to Order Mounjaro in the UK
If you're considering Mounjaro (tirzepatide) for weight management in the UK, you have two main routes: NHS specialist services or private online prescribing. Both require a clinical assessment and a valid prescription from a licensed UK healthcare provider. Understanding your eligibility, the differences between these pathways, and what to expect will help you make an informed decision about whether this dual GIP and GLP-1 receptor agonist is right for you. Use our free BMI calculator to check your starting point, then explore your options below.
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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 Mounjaro Access and NICE Guidance
NICE has approved tirzepatide (Mounjaro) for use within NHS weight management services. You cannot order Mounjaro directly from your GP surgery — it is prescribed only through specialist tier 3 or tier 4 weight management services. Your GP can refer you to these services if you meet eligibility criteria.
NHS eligibility for Mounjaro:
- BMI of 30 kg/m² or above (obesity), or
- BMI of 27–29.9 kg/m² with at least one weight-related health condition (type 2 diabetes, prediabetes, high blood pressure, abnormal cholesterol, sleep apnoea, or cardiovascular disease history)
- For South Asian, Chinese, Black African, or Black Caribbean adults: lower thresholds may apply (BMI 27.5+)
Mounjaro on the NHS is free at the point of use, but waiting times vary significantly by region. Some areas have waiting lists of several months to over a year. Your GP can tell you your local ICB's (Integrated Care Board) status and expected timeline.
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 Prescribing in the UK
Private Mounjaro is available through GPhC-registered online pharmacies without an NHS referral. You complete an online consultation with a UK-licensed prescriber, who assesses your suitability based on your health history, BMI, and weight-related conditions. If approved, a prescription is issued and Mounjaro is dispensed by a pharmacy.
Private costs range from approximately £150–£320 per month depending on your dose. The starting dose is 2.5 mg, titrating up to 15 mg maximum over 20 weeks. Each KwikPen pen contains 4 weekly doses. Private access is faster than NHS (typically 1–2 weeks from consultation to receipt), making it an option if NHS waiting times are long in your area. Try our free GLP-1 weight loss calculator to estimate potential outcomes and understand dose progression before ordering.
- 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.
Can I order Mounjaro directly from my GP?
No. Mounjaro is not available as a standard GP prescription in the UK. You must be referred to a specialist tier 3 or tier 4 weight management service (NHS) or use a private online prescriber. Your GP can refer you to NHS services if you meet eligibility criteria, but this process varies by region and can involve waiting lists.
How much does Mounjaro cost privately in the UK?
Private Mounjaro costs between £150–£320 per month, depending on your dose and the provider. Costs are typically higher at the maximum 15 mg dose. Some providers offer subscription or bundle discounts. Always check that the provider is GPhC-registered and that a UK-licensed prescriber will assess you before dispensing.
What's the difference between ordering Mounjaro on the NHS vs privately?
NHS Mounjaro is free but requires a referral and may involve a long wait (months to 1+ year). Private Mounjaro is faster (1–2 weeks) but costs £150–£320/month. Both require a clinical assessment and prescription from a UK-licensed healthcare professional. NHS access also depends on your local ICB funding and tier 3 service availability.
Do I need a prescription to order Mounjaro in the UK?
Yes. Mounjaro is prescription-only in the UK and cannot be bought over the counter. Both NHS and private routes require a valid UK prescription from a licensed prescriber. Never order Mounjaro from unlicensed or non-UK sources — it may be counterfeit, unsafe, or illegal.
How do I know if I'm eligible for Mounjaro?
Use our free BMI calculator to check your BMI. NHS eligibility requires BMI ≥30, or BMI 27–29.9 with a weight-related health condition. For South Asian, Chinese, Black African, or Caribbean heritage, lower thresholds apply. Private eligibility is assessed by the prescriber during your online consultation and may be broader. Discuss your individual circumstances with your GP or a private prescriber.
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.