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 to Access Mounjaro Injection in the UK
Mounjaro (tirzepatide) is a once-weekly weight loss injection available in the UK through both NHS and private prescription routes. This guide explains how to access Mounjaro, what it costs, and the differences between NHS and private options. Whether you're eligible through your GP or seeking private prescription access, understanding your options helps you make an informed decision about this weekly weight loss injection for your weight management journey.
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.
Private Mounjaro Prescription Cost & Access
In the UK, private Mounjaro prescriptions are available through GPhC-registered online pharmacies following an online clinical assessment with a UK-licensed prescriber. Private costs typically range from £129 to £320 per month, depending on your dose and the provider.
- Starting dose (2.5 mg): approximately £129–£160 per month
- Maintenance dose (5–10 mg): approximately £180–£250 per month
- Maximum dose (15 mg): approximately £280–£320 per month
Each KwikPen contains 4 weeks of injections. A prescriber will assess your health during an online consultation and determine which dose is appropriate for you. You'll need to be assessed as clinically suitable before a prescription is issued. Our GLP-1 weight loss calculator can help you understand potential outcomes at different doses, though individual results vary significantly.
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 Routes: Which is Right for You?
NHS access to Mounjaro is through specialist tier 3 weight management services, typically requiring a GP referral. NHS availability varies widely by region, and waiting lists can extend several months or longer in many areas. Once approved, NHS prescriptions are free, but access depends on your local Integrated Care Board (ICB) funding decisions.
Private access is faster — you can access Mounjaro within days of a successful online consultation without an NHS referral. This makes private prescription the quicker option if you meet clinical eligibility criteria (BMI ≥30, or BMI 27–29.9 with weight-related health conditions). Use our free BMI calculator to check your eligibility status instantly. Private prescriptions require you to pay upfront but offer immediate access without waiting lists.
- 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.
How do I get an online Mounjaro prescription in the UK?
Visit a GPhC-registered pharmacy offering online prescribing. Complete a health questionnaire and have a consultation with a UK-licensed prescriber. If approved, a prescription is issued and dispensed by the pharmacy. The entire process typically takes 24–48 hours. You'll self-inject once weekly at home using the KwikPen device.
What's the difference between NHS and private Mounjaro?
The medication is identical — both contain tirzepatide. The difference is access route and cost. NHS is free but requires a GP referral and specialist assessment with significant waiting times. Private is faster (days, not months) but you pay the cost upfront. Eligibility criteria are the same for both routes.
Do I need a GP referral for private Mounjaro in the UK?
No. Private Mounjaro prescriptions do not require a GP referral. You can access private prescription services directly through an online provider. However, informing your GP about any weight loss medication you're taking is recommended for your medical records.
Is Mounjaro available on the NHS in the UK?
Yes, NICE has approved tirzepatide (Mounjaro) for use within NHS specialist weight management services. However, NHS access is limited to tier 3 services and varies significantly by region. Your GP can refer you, but you'll need to meet local ICB criteria and be prepared for potentially long waiting lists.
How much does a 4-week supply of Mounjaro cost privately?
A 4-week supply (one KwikPen with 4 doses) costs approximately £129–£320 depending on your dose strength. Starting doses (2.5 mg) are cheaper; maximum dose (15 mg) is most expensive. Most people stay on maintenance doses of 5–10 mg long-term, typically costing £180–£250 monthly privately.
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.