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 Access Mounjaro in the UK
Mounjaro (tirzepatide) is available in the UK through two main routes: NHS specialist weight management services and private online prescribing. Access differs significantly depending on which route you choose, your eligibility, and your local NHS provision. Understanding both options helps you decide what's right for your circumstances. This guide explains where Mounjaro is stocked in the UK, how to get a prescription, eligibility criteria, and what to expect from each pathway.
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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 Route: Tier 3 Specialist Services and NICE Approval
NICE has approved tirzepatide (Mounjaro) for use within specialist NHS weight management services, but access is limited to tier 3 (specialist) and tier 4 (bariatric) weight management pathways. You cannot obtain Mounjaro directly from your GP or a standard pharmacy — referral to a specialist weight management service is required.
- Eligibility: BMI of 30 kg/m² or above, or 27–29.9 with weight-related health conditions such as type 2 diabetes, prediabetes, hypertension, or obstructive sleep apnoea. South Asian, Chinese, Black African, and Black Caribbean adults may qualify at lower BMI thresholds (27.5+).
- Access pathway: Ask your GP for referral to your local integrated care board (ICB) tier 3 weight management service. Waiting times vary by region — some services have waiting lists of 6–18 months.
- Assessment: Once referred, a specialist team (doctor, nurse, dietitian) will assess your suitability, health history, and weight loss goals.
- Supply: If approved, Mounjaro is supplied through NHS pharmacies as part of your treatment plan. Doses are titrated gradually (starting 2.5 mg, increasing weekly to a maximum of 15 mg).
Regional availability varies significantly. Some ICBs offer Mounjaro routinely; others have restricted access or are still rolling out services. Contact your GP or local commissioning office for current provision in your area.
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 Route: Online Prescribing and GPhC Pharmacies
Mounjaro is also available privately through UK-licensed prescribers via online consultation and GPhC-registered pharmacies. This route does not require NHS referral or local availability decisions.
- Access: Complete an online health questionnaire and speak with a UK-licensed prescriber (doctor or nurse prescriber). No appointment queue or referral needed.
- Assessment: The prescriber reviews your medical history, current medications, weight, BMI, and health conditions to determine suitability. Same eligibility principles apply as NHS (BMI 27+, relevant health conditions, or BMI 30+).
- Cost: Private prescriptions vary by provider and dose. Typical costs range from approximately £129–£320 per month depending on your current dose and supplier.
- Supply: Once prescribed, your Mounjaro KwikPen is sent to you by post from a regulated UK pharmacy, typically within 2–5 working days.
Use your free GLP-1 weight loss calculator to estimate potential results alongside your doctor's guidance.
- 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 from a regular UK pharmacy without a prescription?
No. Mounjaro is prescription-only in the UK and cannot be purchased over the counter from any pharmacy. You must have a valid UK prescription from a licensed prescriber before any pharmacy can dispense it, whether NHS or private.
What's the difference between NHS and private Mounjaro?
The medication itself is identical. The difference is in access: NHS comes via specialist tier 3 services (free but involves waiting lists and regional variation), while private comes via online prescribing (no waiting list, costs apply, faster access). Both require clinical assessment and a valid prescription.
How long is the NHS waiting list for Mounjaro?
Waiting times vary significantly by region. Some services have waiting lists of 3–6 months; others may wait 12–18 months. Contact your local integrated care board or ask your GP for current waiting times in your area, or check NHS England's specialist commissioning guidance.
What happens if I'm not eligible for NHS Mounjaro?
If your BMI is below 27 and you don't have qualifying weight-related health conditions, you may still explore private prescribing. A private prescriber can assess whether Mounjaro is clinically suitable for you based on your individual health circumstances, independent of NHS tier 3 criteria.
Is Mounjaro the same as Wegovy?
No. Both are weight loss injections, but Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist, while Wegovy (semaglutide) is a GLP-1 agonist only. Mounjaro and Wegovy show different efficacy in clinical trials. Your prescriber can advise which is more suitable for you.
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.