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
Is Wegovy 1.7 Mg Equivalent to Mounjaro? UK Dose Guide
Wegovy 1.7 mg and Mounjaro work through different mechanisms but both are prescription-only weight management injections licensed in the UK. Wegovy is a GLP-1 receptor agonist, whilst Mounjaro (tirzepatide) is a dual GIP and GLP-1 agonist — which means they're not directly equivalent by dose. Understanding how they compare helps you have an informed discussion with your GP or prescriber about which medication might suit your individual health needs. Both are available through NHS specialist tier 3 weight management services or private prescribing in the UK.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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 Wegovy 1.7 Mg Compares to Mounjaro Doses
Wegovy 1.7 mg is typically considered roughly equivalent to Mounjaro 10 mg in terms of clinical effect, though this is an approximation based on practice guidance rather than formal conversion data. The comparison is complicated because:
- Wegovy contains semaglutide (a single GLP-1 agonist)
- Mounjaro contains tirzepatide (a dual GIP and GLP-1 agonist)
- The dual mechanism of Mounjaro may produce stronger appetite suppression for some people
- Individual responses vary significantly
Clinical trial data shows Wegovy at 2.4 mg (the maximum dose) achieved average weight loss of approximately 15% body weight. Mounjaro at 15 mg (the maximum dose) achieved approximately 21% average weight loss — suggesting the dual mechanism may have stronger average effects. However, any switch between medications must be managed by your prescriber and based on your personal health assessment.
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.
Wegovy and Mounjaro on the NHS: UK Prescribing Context
Both Wegovy and Mounjaro are available on the NHS through specialist tier 3 weight management services, though access varies significantly across UK regions and involves lengthy waiting lists in many areas. NICE has approved both medications for use within NHS specialist weight management pathways. However, not all NHS ICBs (Integrated Care Boards) have implemented them, and referral criteria can differ.
Access is faster through private prescribing with a UK-licensed prescriber following an online clinical assessment. Our GLP-1 weight loss calculator can help you estimate potential weight loss at different doses. For NHS access, ask your GP about tier 3 referral; for private prescribing, you'll need to meet eligibility criteria (BMI 30+, or 27+ with weight-related health conditions) and be assessed by a licensed prescriber. Individual results vary, and both medications work best alongside reduced-calorie diet and increased physical activity.
- 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 1.7 mg the same strength as any Mounjaro dose?
Wegovy 1.7 mg is approximately equivalent to Mounjaro 10 mg in clinical effect, but they are not directly interchangeable. Mounjaro's dual mechanism (GIP and GLP-1) may produce stronger average weight loss than Wegovy's single GLP-1 mechanism. Any switch between medications must be managed by your prescriber based on your individual response and health needs.
Which weight loss faster — Wegovy or Mounjaro?
Clinical trial data suggests Mounjaro achieves slightly higher average weight loss (approximately 21% body weight at maximum dose versus 15% for Wegovy). However, individual results vary significantly. Your response will depend on your metabolism, adherence, diet, activity level, and overall health. A prescriber can help you choose based on your circumstances.
Can I switch from Wegovy to Mounjaro on the NHS?
Potentially, but availability varies by region. Your NHS tier 3 specialist weight management service can discuss switching if the first medication isn't giving you the results you need. Private prescribers can also manage switches. There's no formal established conversion — your prescriber will start you on an appropriate Mounjaro KwikPen dose and titrate from there.
What is the main difference between Wegovy and Mounjaro?
Wegovy (semaglutide) activates only the GLP-1 hormone pathway. Mounjaro (tirzepatide) activates both GIP and GLP-1 pathways — the dual mechanism may explain stronger average appetite suppression and weight loss. Both are once-weekly injections available as prescription-only medicines in the UK, with similar side effects but different dose schedules and mechanisms.
How do I know which medication to ask my GP about?
Both are prescription-only and require clinical assessment. Your GP can refer you to a specialist tier 3 service, or you can pursue private prescribing. A licensed prescriber will consider your health history, previous treatments, contraindications, and preferences. Try our GLP-1 weight loss calculator to understand potential outcomes at different doses, and discuss your options with a healthcare professional.
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.