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
What Is 1mg of Wegovy Equivalent to Mounjaro?
Wegovy (semaglutide) 1mg is approximately equivalent to Mounjaro (tirzepatide) 5mg, though there is no official conversion chart between the two medications. Both are once-weekly GLP-1-based injections licensed for weight management in the UK, but they work through different mechanisms. Mounjaro is a dual GIP and GLP-1 receptor agonist, while Wegovy activates GLP-1 alone. Understanding the approximate equivalence can help when comparing costs and access routes in the UK private market.
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.
UK Private Prescription Costs and Access Routes
Both Wegovy and Mounjaro are available privately in the UK through GPhC-registered online pharmacies following an online clinical assessment with a UK-licensed prescriber. Wegovy costs typically range from £129–£199 per month depending on the dose and pharmacy, while Mounjaro generally costs £150–£320 per month at comparable doses. The cost difference reflects Mounjaro's dual mechanism and the higher maximum dose (15mg vs Wegovy's 2.4mg). Private access means you don't require an NHS referral to a tier 3 specialist weight management service, which can involve lengthy waiting lists in many regions. However, prescribers will still assess your eligibility based on BMI thresholds and health conditions during your online consultation. Use our GLP-1 weight loss calculator to compare potential outcomes at different doses of each medication.
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.
NHS vs Private Access: Key Differences
The NHS does approve both tirzepatide and Wegovy for weight management through NICE guidance, but NHS access is limited to specialist tier 3 services via GP referral—availability and waiting times vary significantly by region. Private prescribing offers faster access without NHS referral, though you pay the full cost. When choosing between them, consider: private costs (Wegovy may be slightly cheaper at lower doses), individual tolerability (side effect profiles differ), and clinical preference based on your health history. Our BMI calculator can help you check your eligibility, though a prescriber will make the final assessment. Either medication requires ongoing monitoring and works best alongside dietary changes 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 1mg Wegovy the same strength as 5mg Mounjaro?
Approximately, yes—though there's no official conversion chart. These are approximate clinical equivalences based on clinical trial data and prescriber experience. However, individual response varies significantly, so the "right" dose depends on your personal tolerability and weight loss response, not just the number.
Which is cheaper, Wegovy or Mounjaro, in the UK?
Wegovy is typically slightly cheaper at lower doses (£129–£160/month), while Mounjaro tends to cost more overall (£150–£320/month). However, prices vary between providers and doses. Get individual quotes from different online pharmacies before deciding.
Can I switch from Wegovy to Mounjaro on the NHS?
NHS access to either medication is limited and regional. If you're on NHS Wegovy, switching to Mounjaro would require discussion with your specialist tier 3 service. Private switching is easier—you can consult a private prescriber and switch between medications more flexibly.
How long does a UK online prescription assessment take?
Most online consultations take 24–48 hours from submission to prescription issuance. Some providers offer same-day or next-day prescriptions if you complete your assessment early. The pharmacy then dispatches your medication, typically arriving within 1–3 working days.
Do I need to choose between Mounjaro and Wegovy, or can my GP prescribe either?
Your GP cannot routinely prescribe either for weight management on the NHS—specialist tier 3 services make that decision. Privately, you choose which medication you want assessed for, and a licensed prescriber will determine suitability based on your health profile and preferences. ```
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.