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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Getting Mounjaro in the UK — NHS and Private Routes
Mounjaro (tirzepatide) is a prescription-only weight loss injection available in the UK through two distinct pathways: NHS specialist weight management services and private prescribing via registered online providers. Understanding the differences between these routes — including eligibility criteria, waiting times, and costs — helps you decide which option may be suitable for your circumstances. The NHS provides access through tier 3 specialist services in some regions, whilst private prescribing offers faster access without NHS referral, though at a cost. This guide explains both routes and what you need to know.
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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.
How to Access Mounjaro on the NHS
NHS access to Mounjaro operates through specialist tier 3 weight management services. You cannot obtain Mounjaro directly from your GP — referral to a specialist service is required. NICE has approved tirzepatide for use within NHS weight management services for eligible adults. To access NHS Mounjaro, you must be referred by your GP to your local integrated care board (ICB) weight management service. Eligibility criteria include a BMI of 30 kg/m² or above, or BMI 27–29.9 kg/m² with weight-related health conditions such as type 2 diabetes, prediabetes, high blood pressure, or cardiovascular disease. For South Asian, Chinese, Black African, or Black Caribbean adults, lower BMI thresholds apply — eligibility may begin at BMI 27.5 or above.
However, NHS availability varies significantly by region. Some areas have specialist services with capacity; others have long waiting lists. A few ICBs do not currently offer Mounjaro through the NHS, even if you meet eligibility criteria. This postcode lottery means access is inconsistent across the UK.
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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 Mounjaro Prescribing and NHS Comparison
Private Mounjaro prescribing bypasses NHS waiting lists. Once you meet basic eligibility criteria (BMI ≥27.5 with health conditions or BMI ≥30), a UK-licensed prescriber can issue a prescription following a confidential online consultation. A GPhC-registered pharmacy then dispenses the medication. Private costs typically range from £129 to £280 per month depending on dose, with the KwikPen device holding a four-week supply. Private access does not require NHS referral and treatment can begin within days rather than months.
The trade-off is cost — NHS provides Mounjaro free at point of use for eligible patients (though access varies), whilst private costs accumulate monthly. Use our free GLP-1 weight loss calculator to project potential outcomes at different doses, and our BMI calculator to confirm your current eligibility status.
- 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 free on the NHS?
Yes, if you meet eligibility criteria and your ICB offers it. NICE approves Mounjaro for NHS use, but availability depends on your region and local waiting lists. Contact your GP for referral to your local weight management service to check availability in your area.
How long is the NHS waiting list for Mounjaro?
Waiting times vary significantly by region — from several weeks to over a year in some areas. Many ICBs have lengthy waiting lists or limited Mounjaro availability. Some regions may prioritise patients with type 2 diabetes or serious obesity-related conditions.
What is the cost of private Mounjaro in the UK?
Private prescribing costs range from approximately £129 to £280 per month depending on your dose. Each KwikPen contains four weeks of doses. You may also pay a consultation fee (typically £50–£150) for the initial prescriber assessment.
Is a prescription required for private Mounjaro?
Yes. Mounjaro is prescription-only in the UK. Private access requires an online consultation with a UK-licensed prescriber who will assess your eligibility before issuing a prescription to a GPhC-registered pharmacy.
What is the difference between Mounjaro and Wegovy for UK weight loss?
Both are prescription-only injections licensed in the UK. Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist; Wegovy (semaglutide) is a GLP-1 agonist only. Clinical trials suggest Mounjaro may support slightly greater average weight loss, though individual results vary significantly.
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.