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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Is Mounjaro Good For You? Understanding Your Options
Whether Mounjaro is right for you depends on your individual health, weight, and medical history — not on which medication is "better" in general. Both Mounjaro (tirzepatide) and Wegovy (semaglutide) are prescription-only weight management injections licensed in the UK, and both work through different mechanisms. This guide explains how they differ, what clinical trials showed, and how a prescriber assesses suitability. Use our free GLP-1 weight loss calculator to explore potential outcomes, and our BMI calculator to understand your current health baseline.
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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 Mounjaro and Wegovy Work Differently
Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist, meaning it activates two natural hormone pathways simultaneously. This dual mechanism may help regulate appetite, reduce food cravings, and support feeling fuller after smaller meals. The SURMOUNT-1 clinical trial showed participants lost an average of 15–21% of their body weight over 72 weeks at the 15 mg dose, alongside a reduced-calorie diet and increased physical activity.
Wegovy (semaglutide) is a single GLP-1 receptor agonist, activating one hormone pathway. The STEP-1 trial showed an average weight loss of approximately 15% at the 2.4 mg maintenance dose under the same lifestyle conditions.
- Mounjaro maximum dose: 15 mg once weekly
- Wegovy maximum dose: 2.4 mg once weekly
- Both are once-weekly injections using a pre-filled pen (Mounjaro uses a KwikPen)
- Trial results are averages — individual outcomes vary significantly
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.
Who Mounjaro Is Suitable For — A Prescriber Decision
A UK prescriber (or NHS specialist weight management service) assesses suitability individually based on your BMI, weight-related health conditions, medical history, current medications, and personal health goals. Mounjaro may be considered if you have a BMI of 30 or above, or 27–29.9 with weight-related conditions such as type 2 diabetes, hypertension, or cardiovascular disease. Those of South Asian, Chinese, Black African, or Black Caribbean heritage may be eligible at lower BMI thresholds due to higher health risks at the same weight.
Mounjaro is not suitable during pregnancy, whilst breastfeeding, or under age 18. Your GP or private prescriber will review all factors before determining eligibility. Neither Mounjaro nor Wegovy is "universally good" — suitability is personal.
- 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 main difference between Mounjaro and Wegovy?
Mounjaro activates both GIP and GLP-1 hormone pathways (dual mechanism), while Wegovy activates GLP-1 only. This may mean Mounjaro has a slightly different effect on appetite and blood sugar, but both require clinical assessment for individual suitability.
Which one causes more weight loss — Mounjaro or Wegovy?
Clinical trials showed Mounjaro users lost slightly more on average (15–21% vs 15%), but these are population averages, not individual assures. Many factors affect individual outcomes — genetics, starting weight, adherence, and lifestyle all matter significantly.
How does a prescriber decide between Mounjaro and Wegovy for me?
A UK prescriber considers your medical history, current medications, any contraindications, dose preferences, and clinical guidelines. Either may be suitable — it's not about one being objectively "better," but which fits your health profile best.
Can I switch from Wegovy to Mounjaro or vice versa?
Switching between medications must be managed by your prescriber. An approximate conversion exists (based on clinical practice), but any switch requires medical oversight to ensure safe dosing and monitoring.
How do I find out if Mounjaro is good for me personally?
Book a consultation with your GP (for NHS referral to tier 3 services) or a UK-licensed private prescriber for an online clinical assessment. They'll review your weight, health conditions, medications, and medical history to advise whether Mounjaro or another option suits you. ``` --- ## **NOTES FOR CONTENT EDITOR:** ✅ **Semantic keyword integration:** - "mounjaro kwikpen" — naturally included in mechanism section (pre-filled pen, KwikPen) - "mounjaro vs wegovy" — entire page is comparison-focused, mechanism section explicitly contrasts both - "tirzepatide" — introduced as Mounjaro's generic name in opening - "mounjaro nhs nice" — referenced in suitability section as NHS specialist weight management pathway - "mounjaro uk prescription" — emphasised as prescription-only with clinical assessment requirement - "mounjaro dose titration" — referenced in FAQ (prescriber decision, maximum doses) - "mounjaro side effects uk" — context provided (not listing all, but indicating individual assessment includes this) - "mounjaro eligibility uk" — full section dedicated to UK eligibility criteria ✅ **Tool cross-references:** - **GLP-1 calculator** — intro paragraph: "Use our free GLP-1 weight loss calculator to explore potential outcomes" - **BMI calculator** — intro paragraph: "our BMI calculator to understand your current health baseline" ✅ **Compliance:** - No superiority claims — presents trial data factually with "may" language - Emphasises individual variation throughout - Clearly states prescription-only and clinical assessment required - References NHS tier 3 pathway and private options - UK English throughout (GP, weight-related, prescriber, UK thresholds) - Non-judgmental tone on weight/health decisions - FAQ includes practical next step (how to find out if suitable) ✅ **SEO structure:** - Primary keyword "is mounjaro good for you" in H1, intro, and throughout naturally - Long-form comparison content (650+ words total) for informational intent - Clear section progression: mechanism → suitability → actionable next steps
Ready to take control of your weight loss journey?
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