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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Where Can You Get Mounjaro in the UK?
Mounjaro (tirzepatide) is available in the UK through two main routes: NHS specialist weight management services and private online prescribing following a clinical assessment. Access, eligibility, and timelines differ significantly between these pathways. Understanding your options helps you make an informed decision about whether Mounjaro or alternatives like Wegovy might be suitable for your health goals. This guide explains where to access Mounjaro, how the assessment process works, and key differences compared to other weight management injections available in the UK.
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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 vs Private Access to Mounjaro in the UK
NHS Access: Mounjaro is available through specialist tier 3 and tier 4 weight management services in England, following NICE approval for tirzepatide. You cannot obtain Mounjaro from your GP directly — you need a referral from your GP to a specialist weight management service in your local Integrated Care Board (ICB) area. Availability varies significantly by region, and waiting lists can be very long in many areas, sometimes extending several months to over a year. Once accepted into a specialist service, you'll undergo a comprehensive assessment including blood tests, cardiovascular evaluation, and discussion of lifestyle factors before a prescriber determines eligibility.
Private Access: Mounjaro is available through GPhC-registered online pharmacies following a consultation with a UK-licensed prescriber. Private access does not require an NHS referral and can be significantly faster than NHS routes. You complete an online health questionnaire, a prescriber reviews it, and if suitable, a prescription is issued for dispensing by a registered pharmacy. Private costs typically range from £150–£320 monthly depending on your dose, with treatment starting from the Mounjaro KwikPen starter dose of 2.5 mg.
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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.
Mounjaro vs Wegovy — Key Differences in How to Access
Both Mounjaro and Wegovy are prescription-only GLP-1-based weight management injections available in the UK, but with important differences. Mounjaro is a dual GIP and GLP-1 receptor agonist (tirzepatide), while Wegovy is a GLP-1 receptor agonist only (semaglutide). Clinical trial data shows Mounjaro achieved approximately 15–21% average body weight loss in SURMOUNT trials, compared to around 15% for Wegovy in STEP trials — though individual results vary significantly. Both are accessed identically: through NHS specialist services or private prescribing. The choice between them is a prescriber decision based on your individual health profile, medical history, and any previous medication responses. Our GLP-1 weight loss calculator can help you explore potential outcomes, though a licensed prescriber must assess your suitability before any prescription is issued.
- 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 my GP prescribe Mounjaro directly?
No. In the UK, Mounjaro is only prescribed by specialist weight management services (tier 3 or 4), not by GPs. You need a GP referral to access NHS specialist services in your area. Alternatively, you can access Mounjaro privately through an online consultation with a UK-licensed prescriber.
How long does it take to get Mounjaro on the NHS?
Waiting times vary by region (ICB area). Some areas have waits of several months; others may exceed one year. NHS specialist weight management services are under significant demand. Private access is typically faster, often resulting in a prescription within 1–2 weeks if clinically suitable.
Is Mounjaro available on prescription in all UK regions?
Mounjaro is approved by NICE for use within NHS specialist weight management services, but availability and commissioning varies by ICB region. Some areas have established tirzepatide pathways; others do not. Your GP or local ICB can advise on availability in your area.
What's the difference between accessing Mounjaro and Wegovy?
Both are accessed identically — via NHS specialist services or private prescribing. The choice between Mounjaro (dual GIP+GLP-1) and Wegovy (GLP-1 only) depends on your individual health profile and prescriber assessment. Both require clinical evaluation before prescription.
What happens during a private Mounjaro consultation?
You complete an online health questionnaire covering weight history, medical conditions, medications, and lifestyle. A UK-licensed prescriber reviews it, assesses suitability for tirzepatide, and issues a prescription if appropriate. The prescription is then dispensed by a registered pharmacy, with treatment guidance provided.
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.