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
Do Doctors Prescribe Mounjaro in the UK?
Yes, GPs and specialist doctors do prescribe Mounjaro (tirzepatide) in the UK, but access depends on whether you go through the NHS or private healthcare. Mounjaro is a prescription-only weight management injection licensed in the UK for adults with obesity or overweight with weight-related health conditions. The cost, waiting time, and eligibility criteria differ significantly between NHS and private routes. Understanding how to access Mounjaro and what it costs will help you decide which route is right for you. Use our free BMI calculator above to check your eligibility based on your current weight and height.
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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: NHS vs Private Routes
NHS access: Mounjaro is available through specialist tier 3 and tier 4 weight management services, which your GP can refer you to. However, NHS prescribing availability varies significantly by region — some ICBs (Integrated Care Boards) offer it readily, whilst others have restricted access or very long waiting lists. Your GP cannot simply prescribe Mounjaro from primary care; you must be referred to a specialist weight management service for assessment.
Private access: You can obtain a Mounjaro prescription through private online consultations with UK-licensed doctors without an NHS referral. Private prescriptions are dispensed by GPhC-registered pharmacies. Costs typically range from £129 to £320 per month depending on your dose — the Mounjaro KwikPen comes in six doses (2.5mg, 5mg, 7.5mg, 10mg, 12.5mg, 15mg), with higher doses costing more. You'll need to complete an online health questionnaire and consultation, and if clinically appropriate, you'll receive a private prescription within 24–48 hours.
Comparing routes: The NHS is free but involves referral, specialist assessment, and often significant waiting times. Private routes are faster (typically within 48 hours) but have upfront costs. Many people choose private access when NHS waiting lists are too long.
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 Next Steps
To be eligible for Mounjaro prescription in either route, you typically need a BMI of 30 kg/m² or above, or BMI of 27–29.9 kg/m² with a weight-related health condition (such as type 2 diabetes, hypertension, or sleep apnoea). For South Asian, Chinese, Black African, or Black Caribbean adults, lower BMI thresholds apply — eligibility may start at BMI 27.5 or above. Whether you pursue NHS or private access, you'll undergo a clinical assessment to check for contraindications and ensure tirzepatide is appropriate for you. If you're considering Mounjaro, start by checking your BMI and discussing your weight health with your GP — they can advise on NHS referral or support your private prescription decision. Our GLP-1 weight loss calculator can help you estimate potential weight loss at different Mounjaro doses.
- 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 my GP prescribe Mounjaro directly?
In most cases, no. GPs typically refer you to a specialist tier 3 or tier 4 weight management service, where a specialist doctor prescribes Mounjaro after assessment. Some NHS areas offer specialist prescribing in primary care, but this is rare. Private GPs can prescribe Mounjaro directly after an online consultation without NHS referral.
How much does Mounjaro cost privately in the UK?
Private Mounjaro costs typically range from £129 to £320 per month depending on your dose. Starting doses (2.5mg) are cheaper; maximum doses (15mg) are more expensive. Costs vary between private providers and pharmacies, so it's worth comparing. NHS access is free but involves waiting times and regional availability restrictions.
How long does it take to get Mounjaro on the NHS?
NHS waiting times vary widely by region. Some specialist services have waiting lists of several months to over a year. Private online prescriptions are much faster — typically 24–48 hours from consultation to dispensed prescription. Check your local ICB's weight management service waiting times through your GP.
What does the online consultation for private Mounjaro involve?
You'll complete a health questionnaire covering medical history, current medications, allergies, and weight-related symptoms. A UK-licensed doctor reviews your form and may ask follow-up questions via text or video. If Mounjaro is clinically appropriate, you'll receive a private prescription to send to a GPhC-registered pharmacy for dispensing.
Is Mounjaro the same as Wegovy, and do they have different access routes?
No — Mounjaro (tirzepatide) and Wegovy (semaglutide) are different medications with different mechanisms. Both are prescription-only and available via NHS specialist services or private online prescribing. Mounjaro is a dual GIP and GLP-1 agonist; Wegovy is a GLP-1 agonist only. Access routes and costs are similar for both, though they're different drugs with different dose ranges and side effect profiles.
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.