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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Mounjaro Diet Injection — UK Cost & Access Guide
Mounjaro (tirzepatide) is a prescription-only weekly weight loss injection now available in the UK through both NHS specialist services and private prescription routes. The cost, availability, and access pathway vary significantly depending on whether you pursue NHS or private options. Understanding your choices helps you find the most suitable route for your circumstances. This guide explains current UK pricing, how to access Mounjaro through each pathway, and what the clinical assessment process involves.
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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 Costs & Access Pathways
Private Mounjaro prescriptions in the UK typically cost between £129 and £320 per month, depending on your dose. The 2.5 mg starting dose is usually at the lower end, while the maximum 15 mg dose costs more. A single KwikPen contains four weeks' supply of one dose. Many private online prescribing services offer subscription pricing, allowing you to set up regular deliveries with your chosen pharmacy. You'll need to complete an online clinical assessment with a UK-licensed prescriber before your first prescription is issued. The assessment typically takes 24–48 hours, and medications are then dispatched from a GPhC-registered pharmacy. Some services bundle the consultation and prescription, whilst others charge separately. Costs do not include delivery, which varies by provider but is typically £2–10. Always check whether your chosen provider offers dose adjustment consultations as you titrate upwards through the dose range.
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 Route — Which Is Right For You?
NHS access is free at the point of prescribing but requires referral to a tier 3 specialist weight management service through your GP. NHS availability varies dramatically by region — some areas have significant waiting lists (6–18 months in some ICBs), whilst others have limited capacity. You must meet NICE eligibility criteria (BMI ≥30, or ≥27 with weight-related health conditions). Private access bypasses NHS waiting lists and requires no GP referral, but you pay for the medication and consultation. Private prescribing is faster (typically 24–72 hours from consultation to prescription) and allows you to start immediately. Choose NHS if you qualify, have time to wait, and prefer free prescriptions. Choose private if you want to start quickly or haven't been referred to NHS services. Both routes require clinical assessment — private prescribers still check contraindications, medications, and suitability before issuing a prescription.
- 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 much does Mounjaro cost privately in the UK?
Private Mounjaro costs typically range from £129–£320 per month depending on your dose. Starting doses (2.5–5 mg) are usually at the lower end, whilst higher doses (10–15 mg) cost more. Each KwikPen covers four weeks. Prices vary by pharmacy, so compare options. Always factor in consultation fees (if charged separately) and delivery costs.
Can I get Mounjaro free on the NHS?
Yes, Mounjaro is available free through NHS specialist tier 3 weight management services. However, access requires a GP referral and assessment by a specialist team. Availability varies significantly by region — some areas have long waiting lists. Your GP can advise whether you meet local eligibility criteria and how to access your regional service.
What happens during a private online Mounjaro consultation?
You'll complete a health questionnaire covering your medical history, current medications, weight, height, and health conditions. A UK-licensed prescriber reviews this and may ask follow-up questions. If appropriate, they'll issue a prescription which your pharmacy dispenses. The whole process typically takes 24–48 hours. You'll receive guidance on injection technique and when to start.
Is a weekly weight loss injection cheaper than other options?
Weekly injections like Mounjaro cost more upfront than some oral medications, but less than daily injectable alternatives like Saxenda. Private costs are higher than NHS prescriptions (which are free), but private access avoids NHS waiting lists. Some people find the weekly convenience justifies the cost compared to daily injections or multiple daily tablets.
Do private Mounjaro prescriptions include follow-up consultations?
Most private providers offer follow-up consultations during your dose titration phase, though some charge separately. Check your provider's terms — some include dose adjustment reviews in the initial price, whilst others charge per consultation. NHS specialist services include ongoing monitoring as standard at no additional cost.
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.