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
How to Order Mounjaro in the UK
Mounjaro (tirzepatide) is a prescription-only weight management injection available in the UK through two main routes: NHS specialist services and private online prescribing. To order Mounjaro, you'll need a valid prescription from a UK-licensed prescriber following a clinical assessment. This guide explains both routes, eligibility criteria, and what happens after you order. Understanding your options helps you make an informed decision about accessing this GLP-1 and GIP receptor agonist medication.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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.
Routes to Order Mounjaro in the UK
There are two main ways to access Mounjaro in the UK:
NHS Route: Available through specialist tier 3 and tier 4 weight management services. You'll need a referral from your GP, who can discuss whether you meet NICE eligibility criteria. NHS eligibility typically requires a BMI of 30 or above, or 27–29.9 with weight-related health conditions like type 2 diabetes, hypertension, or sleep apnoea. However, NHS availability varies significantly by region (Integrated Care Board). Some areas have waiting lists of several months or years, whilst others have more rapid access. Your GP can tell you local waiting times.
Private Route: Available through GPhC-registered online pharmacies following a remote clinical assessment with a UK-licensed prescriber. You can order online without an NHS referral. A prescriber reviews your medical history and decides if Mounjaro is suitable for you. If approved, a prescription is issued and the Mounjaro KwikPen is dispensed by the pharmacy. This route typically takes days rather than months.
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.
Eligibility and What Happens After You Order
Before ordering Mounjaro, a prescriber will assess whether you're eligible based on your BMI, health conditions, and medical history. You'll need a BMI of 30 or above, or 27–29.9 with comorbidities. The prescriber will also check for contraindications—Mounjaro is unsuitable if you're pregnant, breastfeeding, under 18, or allergic to tirzepatide.
Once approved and your order is placed, your first Mounjaro KwikPen arrives within days. Each pen contains 4 weekly injections. You'll start on 2.5 mg weekly, with doses titrated upwards every 4 weeks. Use our GLP-1 weight loss calculator to estimate potential results, and our BMI calculator to track your starting BMI and progress over time.
- 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.
Is Mounjaro available on the NHS in the UK?
Yes, Mounjaro is approved by NICE for NHS use in specialist weight management services. However, availability depends on your local Integrated Care Board (ICB), and waiting lists vary widely. Some areas have rapid access, whilst others have several-month delays. Your GP can refer you and tell you local waiting times.
Can I order Mounjaro privately without seeing the NHS?
Yes. You can order Mounjaro from a GPhC-registered online pharmacy following a remote clinical assessment with a UK-licensed prescriber. You do not need an NHS referral. If the prescriber approves you, a prescription is issued and your order is dispensed within days. This is often faster than NHS routes.
What is the Mounjaro KwikPen?
The KwikPen is Mounjaro's delivery device—a pre-filled pen injector containing 4 doses of tirzepatide. Each dose is 0.5 ml and is injected once weekly into your stomach, thigh, or upper arm. After 4 weeks (4 injections), you dispose of the pen and start a new one.
What are the starting and maximum Mounjaro doses?
You start on 2.5 mg weekly for 4 weeks, then increase to 5 mg weekly. Your prescriber titrates the dose every 4 weeks up to a maximum of 15 mg weekly, depending on your response and tolerance. Most people reach maintenance at 10 mg or 15 mg.
What health conditions make me eligible for Mounjaro?
Eligible conditions include type 2 diabetes, prediabetes, hypertension, dyslipidaemia (abnormal blood fats), obstructive sleep apnoea, and history of cardiovascular disease. You need a BMI of 30 or above, or 27–29.9 with at least one of these conditions. South Asian, Chinese, Black African, or Black Caribbean adults may qualify at lower BMI thresholds.
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.