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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What Is the Wegovy 1.7 Equivalent to Mounjaro?
Many people wonder how Wegovy 1.7mg compares to Mounjaro doses. The approximate equivalent is Mounjaro 10mg, though this is not an official conversion chart—prescribers individualise doses based on your response and tolerance. Both medications work differently: Wegovy is a GLP-1 only agonist, while Mounjaro is a dual GIP and GLP-1 agonist, which may explain why some people respond differently to each. Understanding these differences helps you discuss options with your GP when considering weight loss medication in the UK.
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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 Do Wegovy and Mounjaro Compare?
Wegovy (semaglutide) and Mounjaro (tirzepatide) are both prescription-only weight loss injections licensed in the UK, but they work through different mechanisms. Wegovy activates only the GLP-1 pathway, whilst Mounjaro activates both GIP and GLP-1 pathways—this dual action may contribute to slightly stronger appetite suppression in some users.
- Wegovy maximum dose: 2.4mg once weekly
- Mounjaro maximum dose: 15mg once weekly
- Approximate equivalence: Wegovy 1.7mg ≈ Mounjaro 10mg (based on clinical practice, not official guidance)
In the STEP-1 trial (Wegovy), participants lost an average of 14.9% body weight at 2.4mg. In the SURMOUNT-1 trial (Mounjaro), the 10mg dose achieved approximately 19.5% average weight loss—but these results cannot be directly compared as trial populations, diets, and activity levels differed. Individual results vary significantly with both medications.
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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.
Which Medication Might Be Right for You?
Your GP or prescriber will assess which medication suits you based on your medical history, other conditions, and how your body responds. Both Mounjaro and Wegovy require a prescription and clinical assessment—neither is available over the counter.
In the NHS, access is through specialist tier 3 weight management services, which often have waiting lists. Privately, both are available through GPhC-registered online pharmacies following an online consultation. Try our GLP-1 weight loss calculator to estimate potential weight loss at different doses, and use our BMI calculator to check whether you meet eligibility criteria (BMI 30+ or 27+ with weight-related health conditions). Individual prescriber guidance is essential—do not switch between medications without professional oversight.
- 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.
Is Wegovy 1.7mg the same as Mounjaro 10mg?
Approximately, yes. The doses are considered rough clinical equivalents based on trial data and prescriber experience, but there is no official conversion chart. Both medications work differently—Wegovy is GLP-1 only, Mounjaro is dual GIP+GLP-1—so responses may differ between individuals. Your prescriber will tailor the dose to your needs.
Which causes more weight loss, Wegovy or Mounjaro?
Clinical trials suggest Mounjaro may produce slightly stronger weight loss on average (up to 21% at maximum dose vs 15% for Wegovy), but this depends on the individual, dose, diet, and activity level. Both are effective; which one suits you best requires a clinical assessment by your prescriber.
Can I switch from Wegovy to Mounjaro?
Yes, but only under prescriber guidance. Your GP or specialist will assess your response to Wegovy, check your health status, and determine an appropriate starting dose for Mounjaro if a switch is recommended. Do not self-switch between prescription medications.
What is the difference between tirzepatide and semaglutide?
Tirzepatide (Mounjaro) is a dual GIP+GLP-1 agonist, whilst semaglutide (Wegovy) is a GLP-1 agonist only. The dual mechanism in tirzepatide may enhance appetite regulation and fat utilisation, potentially explaining stronger weight loss in some trials—but individual variation is significant.
How do I access Wegovy or Mounjaro on the NHS in the UK?
Request a referral to your local tier 3 specialist weight management service from your GP. NHS access is limited and varies by region; waiting lists can be lengthy. Private access is available through online prescribers and GPhC-registered pharmacies with a clinical assessment.
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.