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 Order Mounjaro in the UK
Ordering Mounjaro (tirzepatide) in the UK involves two main routes: NHS specialist services or private prescription through an online consultation. This guide explains how to access Mounjaro, what it costs, and what the prescription process involves. Understanding your eligibility and options can help you make an informed decision about whether this prescription-only weight management injection is right for you.
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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 Mounjaro Costs in the UK
Private prescription costs vary by dose and provider, typically ranging from £129 to £320 per month depending on which strength you're prescribed. Each Mounjaro KwikPen contains four weekly injections, so one pen covers one month of treatment. Starting doses (2.5 mg) are generally at the lower end of this range, while higher maintenance doses (10 mg to 15 mg) cost more. Some private providers offer tiered pricing structures or discounts for purchasing multiple months upfront. Additional costs may include the initial online consultation fee (typically £15–£50) and GP-requested baseline health checks. It's important to note that private Mounjaro prescriptions are not available on the NHS prescription prepayment certificate. Before ordering, use our GLP-1 weight loss calculator to understand potential weight loss projections at different doses, which can help inform your decision about which dose might be appropriate for you following clinical assessment.
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 Access Routes
NHS access requires referral to a tier 3 specialist weight management service from your GP, but availability and waiting times vary significantly by region and integrated care board (ICB). Many areas have waiting lists of months or even years. Private access is faster — you can request an online consultation with a UK-licensed prescriber without needing an NHS referral, and if approved, your prescription can be dispensed within days. The private route requires you to meet eligibility criteria (BMI 30 or above, or 27+ with weight-related conditions like type 2 diabetes or hypertension) and may involve providing blood pressure readings or recent blood work. Both routes are prescription-only and require clinical assessment. Your prescriber will review your medical history, current medications, and suitability before issuing a Mounjaro UK 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 order Mounjaro online in the UK without seeing my GP first?
Yes. Through private online prescribing, you can complete a consultation with a UK-licensed prescriber without a GP referral. The prescriber will assess your eligibility based on your health information. However, the NHS route does require a GP referral to a specialist weight management service first.
How much does a month's supply of Mounjaro cost privately?
Private costs typically range from £129 to £320 per month depending on dose. Starting doses (2.5 mg) are usually cheaper, while higher maintenance doses (15 mg) are more expensive. Prices may vary between providers, and some offer discounts for multi-month purchases.
What happens after I receive my Mounjaro prescription?
You'll receive a KwikPen containing four weeks of weekly injections. You inject once weekly at the same time each week, rotating injection sites between your stomach, thigh, or upper arm. Follow your prescriber's dose escalation schedule — you typically stay on each dose for at least four weeks before increasing.
Can I switch from private Mounjaro to NHS prescription?
Not directly. If you're receiving Mounjaro privately and wish to switch to NHS provision, you would need to discuss this with your GP and be referred to an NHS tier 3 specialist service. However, NHS availability varies by region and may involve a waiting list.
What if I don't meet the eligibility criteria for Mounjaro?
If your BMI is below 27 without weight-related health conditions, Mounjaro may not be appropriate for you. Your prescriber will assess this. Alternatively, your GP can discuss other weight management options through NHS tier 1 or 2 services, which may include dietitian support or behaviour change programmes.
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.