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 Access Mounjaro Weight Loss Injections in the UK
Mounjaro (tirzepatide) is available in the UK as a prescription-only weight loss injection, but accessing it depends on whether you pursue NHS or private routes. NHS access involves referral to specialist weight management services, whilst private prescription offers faster access through online clinical assessment. Understanding your options, costs, and eligibility criteria helps you make an informed decision about this weekly weight loss injection. This guide explains both pathways and what to expect.
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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 and Access Route
Private prescription Mounjaro is available through GPhC-registered online pharmacies in the UK following a clinical assessment. Costs typically range from £129 to £320 per month depending on your dose, with most people paying around £200–£250 monthly for maintenance doses (10mg or 15mg). Prices vary slightly between providers. You do not need NHS referral for the private route — you book an online consultation with a UK-licensed prescriber, who assesses whether Mounjaro is appropriate for you based on your medical history and BMI. If approved, a prescription is issued and dispensed by a registered pharmacy. The entire private process usually takes 2–7 days from consultation to first injection. Many people choose private access to avoid NHS waiting lists, which can extend several months to over a year in some regions. Your prescriber will discuss dose titration (starting at 2.5mg and increasing by 2.5mg every 4 weeks up to 15mg maximum) and provide injection technique guidance.
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 Access: Referral, Availability, and Timeline
NHS access to Mounjaro is through specialist tier 3 or tier 4 weight management services, not standard GP prescription. Your GP can refer you if you meet criteria: BMI of 30 or above, or 27–29.9 with weight-related health conditions such as type 2 diabetes, hypertension, or sleep apnoea. NICE has approved tirzepatide (Mounjaro) for NHS use, but availability varies significantly by region (Integrated Care Board). Some areas offer it routinely; others have limited supply or long waiting lists exceeding 12 months. Once referred, you'll attend specialist assessment appointments before treatment begins. The NHS route is free at point of use (no prescription charge), making it ideal if you can access it. However, regional variation means private prescription via online consultation may be faster for many people despite the cost.
- 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 typically costs £129–£320 per month depending on dose. Most people on maintenance doses pay £200–£250 monthly. Prices vary between GPhC-registered providers. Initial doses (2.5mg–5mg) cost less; higher doses (10mg–15mg) cost more. Always confirm pricing before starting treatment.
Can I get Mounjaro on the NHS?
Yes, Mounjaro is NICE-approved for NHS specialist weight management services. You need GP referral to tier 3/4 services and must meet eligibility criteria: BMI ≥30 or 27–29.9 with weight-related health conditions. Availability and waiting times vary by region — some areas have long delays.
How quickly can I get Mounjaro privately?
Private prescription Mounjaro typically takes 2–7 days from your online consultation to receiving your first KwikPen. NHS access is usually much slower, with waits of 3–12+ months depending on your region and specialist service capacity.
What's the difference between NHS and private Mounjaro access?
NHS is free but involves GP referral, specialist assessment, and waiting lists (often several months). Private is faster (days) but costs £129–£320 monthly. Both require clinical assessment and prescription from a UK-licensed prescriber.
Do I need to be overweight to access Mounjaro?
Mounjaro requires a BMI of at least 27 for those with weight-related health conditions (diabetes, hypertension, sleep apnoea) or BMI 30+ without conditions. Your prescriber will assess whether you meet criteria. Use our free BMI calculator to check your personal BMI instantly.
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.