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 Get Mounjaro Online in the UK
Mounjaro (tirzepatide) is a prescription-only weekly weight loss injection available in the UK through both NHS specialist services and private online prescribing. This guide explains eligibility criteria, how each route works, and what to expect. Whether you're considering NHS access or private prescription options, understanding the differences helps you find the right pathway for your situation. Use our free BMI calculator above to check your current BMI and see if you might meet eligibility thresholds.
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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 Access to Mounjaro in the UK
In the UK, Mounjaro (tirzepatide) is approved for NHS use within specialist weight management services (tier 3 and 4). Access is through referral to your local integrated care board (ICB) weight management service, not directly from your GP.
- Eligibility: BMI 30+ (obesity) or BMI 27–29.9 (overweight) with weight-related health conditions such as type 2 diabetes, hypertension, or sleep apnoea
- Referral route: Your GP refers you to tier 3 specialist services in your area
- Ethnicity consideration: South Asian, Chinese, Black African, or Black Caribbean adults may qualify at BMI 27.5+
- Availability: Varies significantly by region; waiting lists can be several months to over a year in many areas
- Clinical assessment: Specialist team assesses suitability before prescription
NICE has approved tirzepatide for weight management in the NHS, but regional variation in funding and availability remains a significant factor.
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 Online Mounjaro Prescription in the UK
Private online prescribing offers faster access to Mounjaro without NHS waiting lists. Licensed UK prescribers conduct online consultations and issue prescriptions if clinically appropriate; GPhC-registered pharmacies then dispense the medication.
- No NHS referral needed
- Typically available within days rather than months
- Cost ranges from approximately £129–£320 per month depending on dose
- Must meet same eligibility criteria (BMI and health conditions)
- Prescriber assesses suitability based on your health history
- Medication delivered to your home as pre-filled KwikPen injectors
Both routes require the same clinical assessment — the difference is speed and cost. Try our free GLP-1 weight loss calculator to explore potential outcomes at different 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 I get Mounjaro on the NHS in the UK?
Yes, Mounjaro (tirzepatide) is approved for NHS use within specialist tier 3 weight management services. You need a GP referral to your local integrated care board service. However, waiting lists vary — some areas have waits of 12+ months. Eligibility requires BMI 30+ or BMI 27–29.9 with weight-related health conditions.
What's the difference between NHS and private Mounjaro prescription?
NHS access is through specialist services (slower, free at point of use) while private online prescribing is faster (days vs months) but costs £129–£320/month. Both require clinical assessment and the same eligibility criteria. Private option avoids NHS waiting lists but requires upfront cost.
How quickly can I get Mounjaro online privately?
Private online prescribing is typically faster — usually within 2–7 days from consultation to first prescription. NHS specialist services can take several months to over a year depending on your region. Speed is the main advantage of private online prescribing in the UK.
What doses of Mounjaro are available in the UK?
Mounjaro comes in six doses: 2.5 mg (starting), 5 mg, 7.5 mg, 10 mg, 12.5 mg, and 15 mg (maximum). Each is a once-weekly injection via pre-filled KwikPen. Your prescriber starts at 2.5 mg and increases every 4 weeks based on tolerance and response.
Am I eligible for Mounjaro through the NHS?
NHS eligibility requires BMI 30+ or BMI 27–29.9 with weight-related conditions (diabetes, hypertension, sleep apnoea, cardiovascular disease). South Asian, Chinese, Black African, or Black Caribbean adults may qualify at BMI 27.5+. A GP referral to your local tier 3 service triggers assessment. Use our BMI calculator to check your starting point.
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.