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 Get Prescribed Mounjaro in the UK
Getting prescribed Mounjaro (tirzepatide) in the UK involves two main routes: through the NHS specialist weight management service, or via a private online prescription following a clinical assessment. Access, costs, and timelines differ significantly between these pathways. This guide explains how each route works, what to expect, and what Mounjaro eligibility looks like in UK healthcare. Our free GLP-1 weight loss calculator can help you estimate potential outcomes if you do proceed with treatment.
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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.
Private Prescription Route: Cost and Access in the UK
The private online prescription route is currently the most straightforward way to access Mounjaro in the UK. This involves a consultation with a UK-licensed prescriber via an online platform, followed by a prescription dispensed by a GPhC-registered pharmacy if clinically appropriate.
- Cost per month: Approximately £160–£320 depending on your dose. A Mounjaro KwikPen containing 4 weekly doses (one month's supply) costs between £180–£360 in most cases.
- Consultation fee: Usually £15–£30 for the initial online assessment, sometimes waived if you proceed with a prescription.
- Timeline: You can typically receive your first prescription within 24–48 hours of completing your online assessment.
- Dose titration costs: Each dose escalation (2.5 mg → 5 mg → 7.5 mg, etc.) requires a new prescription and a new KwikPen, so monthly costs remain consistent as you increase dose.
Private access does not require an NHS referral and is available regardless of your local NHS specialist service availability.
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 Route and Online Assessment Process
Accessing Mounjaro through the NHS specialist weight management service requires a GP referral to tier 3 or 4 weight management services in your region. However, NHS availability is extremely limited and varies significantly by area. Waiting lists can extend from several months to over a year in many regions.
When pursuing private online prescription, you'll complete a health questionnaire covering your medical history, current medications, weight, height, and weight-related health conditions. A UK-licensed prescriber reviews this and may approve a prescription if you meet eligibility criteria. You'll also be asked about your understanding of Mounjaro's side effects and your commitment to lifestyle changes. Use our free BMI calculator to confirm your BMI before your assessment — most prescribers will request this information.
- 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 is the actual monthly cost of Mounjaro in the UK?
A one-month supply of Mounjaro (one KwikPen with 4 weekly doses) costs between £180–£360 depending on your dose and which pharmacy dispenses it. Starting dose (2.5 mg) tends to be at the lower end; higher doses (12.5–15 mg) at the upper end. Prices vary slightly between providers.
Is Mounjaro available on the NHS?
Yes, Mounjaro is NICE-approved for NHS use, but access is through specialist tier 3/4 weight management services only — not standard GP prescription. Availability is extremely limited and regional waiting lists are typically very long. Private prescription is usually faster.
What happens during an online Mounjaro consultation?
You complete a detailed health questionnaire covering your medical history, current medications, BMI, and weight-related health conditions. A UK-licensed prescriber reviews this within 24 hours. If approved, a prescription is issued and sent to a pharmacy. If concerns exist, the prescriber may request more information or decline the prescription.
How quickly can I get Mounjaro prescribed privately?
Most private consultations are assessed within 24–48 hours. If approved, your prescription can be dispensed the same day or next working day. You could have your first KwikPen within 2–3 days of starting the consultation process.
Am I eligible for Mounjaro?
You may be eligible if you have a BMI of 30 or above, or 27–29.9 with weight-related health conditions (type 2 diabetes, high blood pressure, sleep apnoea, cardiovascular disease). South Asian and Black African/Caribbean adults may be eligible at lower BMI. A prescriber will assess your individual eligibility during consultation.
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.