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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Can You Get Mounjaro From a Pharmacy in the UK?
Yes, you can get Mounjaro from a UK pharmacy — but only with a valid prescription from a licensed healthcare professional. Mounjaro (tirzepatide) is a prescription-only weight management injection available through both NHS specialist services and private online prescribing. Access depends on your eligibility, which is assessed individually based on your BMI and health conditions. This guide explains how to access Mounjaro through UK pharmacies and compares it with the alternative weight loss injection, Wegovy.
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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 vs Wegovy in UK Pharmacies
Mounjaro (tirzepatide) and Wegovy (semaglutide) are both prescription-only weight management injections available through UK pharmacies, but access routes and mechanisms differ. Mounjaro is a dual GIP and GLP-1 receptor agonist, whilst Wegovy is a GLP-1-only agonist. Both require a clinical assessment before prescription. Through NHS specialist tier 3 weight management services, both medications may be available — though waiting lists vary significantly by region. Via private online prescribing, both can be prescribed following an online consultation with a UK-licensed prescriber and dispensed by GPhC-registered pharmacies. You can use our free GLP-1 weight loss calculator to explore potential outcomes at different doses of either medication, helping you understand what might be suitable for your situation.
- Mounjaro: Doses 2.5 mg to 15 mg weekly; average weight loss ~15–21% of body weight in trials
- Wegovy: Doses 0.25 mg to 2.4 mg weekly; average weight loss ~15% of body weight in trials
- Both require reduced-calorie diet and physical activity alongside medication
- Individual results vary significantly — clinical trial averages do not assures personal outcomes
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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 Prescription Requirements
To receive either Mounjaro or Wegovy from a UK pharmacy, you must meet NHS eligibility criteria: BMI of 30 or above, or BMI of 27–29.9 with at least one weight-related health condition (type 2 diabetes, high blood pressure, dyslipidaemia, sleep apnoea, or cardiovascular disease history). Adults of South Asian, Chinese, Black African, or Black Caribbean heritage may have lower thresholds due to higher metabolic risk at lower BMI levels. A prescriber will assess your individual suitability during a clinical consultation — this is not automatic based on BMI alone. You cannot obtain either medication without a prescription. Check your BMI quickly using our free BMI calculator to determine whether you may fall within eligibility ranges, then discuss options with your GP or a private prescriber.
- 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.
What's the difference between Mounjaro and Wegovy?
Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist, whilst Wegovy (semaglutide) is GLP-1-only. In clinical trials, Mounjaro showed average weight loss of 15–21%, Wegovy showed approximately 15%. Both are once-weekly injections. Mounjaro starts at 2.5 mg; Wegovy starts at 0.25 mg. Individual suitability depends on your health profile — your prescriber will advise which is appropriate.
Can I buy Mounjaro or Wegovy without a prescription?
No. Both are prescription-only medicines in the UK. You must have a valid prescription from a UK-licensed healthcare professional (GP, specialist, or online prescriber) before any GPhC-registered pharmacy can dispense either medication. Prescriptions are issued only after clinical assessment.
How long does it take to get Mounjaro on the NHS?
NHS access involves referral to a specialist tier 3 weight management service. Waiting times vary significantly by region — some areas have waiting lists of several months to over a year. Private online prescribing is typically faster, with prescriptions often issued within days, though costs are higher than NHS provision.
What happens if I don't meet the eligibility criteria for Mounjaro or Wegovy?
If your BMI is below 27 or you have no weight-related health conditions, you may not be eligible for either medication via NHS or private prescribing. Your GP can discuss alternative weight management options, such as structured lifestyle programmes, lower-calorie diets, or referral to tier 2 community services.
Are there other weight loss injections available in the UK besides Mounjaro and Wegovy?
Yes. Saxenda (liraglutide) is also licensed for weight management in the UK — it's a GLP-1 agonist but given as a daily injection rather than weekly. Eligibility and access are similar to Mounjaro and Wegovy. Your prescriber will discuss which option suits your situation best.
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.