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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Mounjaro vs Botox — Understanding the Difference
Mounjaro and Botox are often mentioned together online, but they are completely different treatments with different purposes. Botox is a cosmetic injection used to reduce facial wrinkles, whilst Mounjaro (tirzepatide) is a prescription-only weight management injection. This guide clarifies what each treatment does, how they differ, and what you need to know if you're considering prescription weight loss medication in the UK. Understanding these distinctions helps you make informed decisions about your health.
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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.
What Are Mounjaro and Botox — and How Do They Differ?
Botox (botulinum toxin) is a cosmetic injection administered by aestheticians or cosmetic professionals. It temporarily paralyses facial muscles to reduce the appearance of wrinkles and fine lines. Botox is not a pharmaceutical medication and is not prescribed by GPs — it's a cosmetic procedure available privately.
Mounjaro (tirzepatide) is a prescription-only injectable medication licensed in the UK for weight management in adults. It is a dual GIP and GLP-1 receptor agonist — meaning it activates two natural hormone pathways to help regulate appetite, reduce food cravings, and support feeling fuller after meals. Unlike Botox, Mounjaro requires a clinical assessment from a licensed prescriber before being dispensed.
- Botox: cosmetic, temporary (results last 3–4 months), no medical benefit
- Mounjaro: medical treatment, ongoing prescription, targets appetite regulation
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.
Mounjaro vs Wegovy — How Do They Compare for Weight Management?
Both Mounjaro and Wegovy (semaglutide) are prescription-only weight management injections licensed in the UK, but they work via different mechanisms. Mounjaro uses a dual GIP and GLP-1 agonist approach — activating two hormone pathways simultaneously — whilst Wegovy is a GLP-1-only agonist. In clinical trials, Mounjaro users lost an average of 15–21% of body weight over 72 weeks, whilst Wegovy users lost approximately 14.9% over 68 weeks. Both are given as once-weekly injections and both require a prescriber's assessment. Individual results vary significantly. Use our free BMI calculator above to check whether you may be eligible for either treatment, and our GLP-1 weight loss calculator to explore potential outcomes based on different doses. Your GP or a licensed prescriber will determine which medication is most suitable for your individual health profile.
- 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 Botox used for weight loss?
No. Botox is purely cosmetic and designed to reduce facial wrinkles by temporarily paralyzing facial muscles. It has no effect on appetite, metabolism, or weight. Do not confuse cosmetic Botox with prescription weight loss medications like Mounjaro or Wegovy.
Can I get Mounjaro on the NHS in the UK?
Mounjaro is available through NHS specialist tier 3 weight management services in some regions, though availability and waiting lists vary significantly. Many people access it privately through online clinical assessments with UK-licensed prescribers. Your GP can advise on NHS pathways in your area.
What's the main difference between Mounjaro and Wegovy?
Mounjaro is a dual GIP and GLP-1 receptor agonist (activating two hormone pathways), whilst Wegovy is a GLP-1-only agonist. Both are once-weekly injections, but Mounjaro reaches a higher maximum dose (15mg vs 2.4mg). Clinical trial data shows slightly higher average weight loss with Mounjaro, but individual results vary.
Do I need a prescription for Mounjaro in the UK?
Yes. Mounjaro is prescription-only and requires a clinical assessment from a UK-licensed prescriber. You cannot buy it without a valid prescription. Following your assessment, a GPhC-registered pharmacy will dispense it if deemed appropriate for your health profile.
Are Mounjaro injections painful?
Mounjaro is a small, once-weekly subcutaneous injection (under the skin). Most users report minimal discomfort — the needle is very fine. Injection site reactions (redness, bruising, mild pain) are common but usually temporary. Your prescriber will provide guidance on injection technique.
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.