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
Where Can I Buy Mounjaro in the UK?
Mounjaro (tirzepatide) is a prescription-only weight management injection that cannot be bought without a valid prescription from a UK-licensed prescriber. Access in the UK comes through two main routes: NHS specialist weight management services or private online prescribing clinics. This guide explains both options, eligibility criteria, and what to expect at each stage. Understanding where and how to access Mounjaro helps you make an informed decision about weight management support.
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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.
NHS Access to Mounjaro
NHS Mounjaro access is through tier 3 or tier 4 specialist weight management services, not standard GP prescription. You'll need a referral from your GP to a specialist service in your area. NICE has approved tirzepatide for use within NHS specialist weight management services for adults with a BMI of 30 or above, or 27–29.9 with weight-related health conditions.
- Your GP can refer you to the specialist weight management service in your local Integrated Care Board (ICB)
- Waiting lists vary significantly by region — some areas have waits of several months to over a year
- The specialist service will conduct a full assessment before prescribing
- If prescribed on the NHS, the cost is covered (no patient charge beyond prescription fees)
Ask your GP whether your local NHS service currently offers Mounjaro, as availability and waiting times vary across the UK.
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.
Private Access to Mounjaro
Private prescribing is available through GPhC-registered online clinics without an NHS referral. You complete an online consultation with a UK-licensed prescriber, who assesses your eligibility based on your health history, BMI, and medical conditions. If approved, a prescription is issued and dispensed by a registered pharmacy.
- Private access is faster than NHS — typically 24–48 hours from consultation to prescription
- Costs vary by dose, ranging from approximately £129–£320 per month
- You'll need to reorder each month (or every 4 weeks per dose cycle)
- The prescriber will ask about your GP, blood pressure, weight history, and any weight-related health conditions
Both routes require a clinical assessment — Mounjaro is not available to purchase without 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.
Can I buy Mounjaro over the counter or online without a prescription?
No. Mounjaro is a prescription-only medicine in the UK and cannot be purchased without a valid prescription from a licensed prescriber. Any site offering Mounjaro without a prescription is illegal. Always use GPhC-registered online clinics or NHS services.
What's the difference between buying Mounjaro on the NHS vs privately?
NHS access is through specialist weight management services (requires GP referral, longer waits, no cost beyond prescription fees). Private access is faster (24–48 hours) but you pay for each month's supply (£129–£320 depending on dose). Both require clinical assessment.
Do I need to see my GP before getting Mounjaro?
For NHS access, yes — your GP makes the referral to specialist services. For private access, you can start an online consultation directly with a private prescriber without a GP referral, though they may contact your GP for medical history.
How much does Mounjaro cost privately in the UK?
Private costs range from approximately £129–£320 per month depending on your dose (2.5mg to 15mg). You'll reorder monthly as each KwikPen provides a 4-week supply. Prices vary between private clinics, so it's worth comparing.
Is Mounjaro covered by the NHS for all adults with excess weight?
No. NHS access is typically for adults with a BMI of 30 or above, or 27–29.9 with weight-related conditions like type 2 diabetes, high blood pressure, or sleep apnoea. Your local NHS service determines final eligibility. Availability also varies by region.
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.