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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Where to Buy Mounjaro in the UK
Mounjaro (tirzepatide) is a prescription-only weight loss injection available in the UK through two main routes: NHS specialist services and private online prescribing. The cost and access pathway depend on which route you choose. This guide explains how to access Mounjaro, what each route costs, and what to expect during the process. If you're considering Mounjaro as a weight management option, understanding your access routes helps you make an informed decision about whether it's right for you.
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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.
Mounjaro Cost and Access in the UK
Mounjaro is available through two pathways in the UK:
- NHS route: Free on the NHS if prescribed through a specialist tier 3 weight management service, but access varies significantly by region. Many areas have waiting lists of several months to over a year. Your GP can refer you to your local specialist service, but eligibility is typically limited to adults with a BMI of 30 or above (or 27–29.9 with weight-related health conditions). Not all ICBs (Integrated Care Boards) currently fund tirzepatide.
- Private route: Available through GPhC-registered online pharmacies following a clinical assessment with a UK-licensed prescriber. Costs range from approximately £129 to £320 per month depending on the dose. A weekly injection KwikPen contains 4 doses (4 weeks' supply). Private access does not require NHS referral and is typically available within days rather than months. You pay upfront for each prescription.
Many people choose the private route due to shorter waiting times, even if they are eligible for NHS treatment. NHS availability is postcode-dependent, so your local options depend on your region.
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.
What to Expect: NHS vs Private Access
NHS route: Contact your GP to ask for a referral to your local tier 3 weight management service. You'll be assessed for eligibility, which may involve blood tests and health checks. If approved, you'll be added to a waiting list. Once you start Mounjaro, the NHS covers the cost entirely.
Private route: Complete an online consultation with a UK-licensed prescriber. You'll answer health questions and may need blood pressure checks. If approved, a prescription is issued and sent to a GPhC-registered pharmacy. Your medication is delivered to your home. You can use our GLP-1 weight loss calculator to explore projected outcomes at different doses before committing to treatment.
- 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 get Mounjaro on the NHS without a waiting list?
NHS availability depends on your local ICB. Some areas offer access with shorter waits; others have waiting lists of 12+ months. Private access is typically faster (days rather than months) but costs £129–£320 per month depending on the dose.
Is Mounjaro cheaper on the NHS or privately?
On the NHS, Mounjaro is free once prescribed. Privately, you pay per prescription (4 weeks' supply per KwikPen). However, NHS access requires a referral and may involve a long wait. Many people choose private access for speed despite the cost.
Do I need a GP referral to buy Mounjaro privately?
No. Private prescribing does not require NHS referral. You complete an online consultation directly with a UK-licensed prescriber. If approved, a prescription is issued and dispensed by a GPhC-registered pharmacy without NHS involvement.
What happens after my clinical assessment for private Mounjaro?
If approved, your prescription is issued and sent to the pharmacy. Your Mounjaro KwikPens are typically delivered to your home within a few days. You'll start at 2.5mg and increase gradually, injecting once weekly.
How long does the private prescription process take?
Most online consultations are completed within 24 hours. Once approved, prescriptions are usually dispensed and delivered within 2–5 working days. This makes private access much faster than NHS waiting lists in most regions.
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.