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 Mujaro and How Does It Work?
Mujaro is a brand name for tirzepatide, a prescription-only weight management injection licensed in the UK. It works differently from other weight loss medications because it activates two natural hormone pathways — GIP and GLP-1 — rather than just one. This dual mechanism may help reduce appetite, control food cravings, and support feeling fuller after smaller meals. If you're exploring weight management options as part of your UK health journey, it's important to understand how this medication works, who it's suitable for, and how to access it through NHS or private routes.
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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 Mujaro Works and What Makes It Different
Mujaro is a dual GIP and GLP-1 receptor agonist — a key difference from other weight loss injections like Wegovy (semaglutide), which only target GLP-1. By activating both pathways, Mujaro may provide additional appetite control and metabolic support.
The medication works by:
- Signalling to the brain that you feel full, reducing overall hunger
- Slowing how quickly food leaves your stomach
- Helping regulate how your body uses fat
- Supporting blood sugar stability (important for weight management)
Clinical trials showed that adults taking Mujaro lost an average of 15–21% of their body weight over 72 weeks, though individual results vary significantly. Weight loss was achieved alongside a reduced-calorie diet and increased physical activity — the medication is not a replacement for lifestyle changes. Using our free GLP-1 weight loss calculator, you can explore potential weight loss projections at different doses to understand what might be realistic for your situation.
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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.
UK Eligibility and How to Access Mujaro
In the UK, Mujaro may be prescribed for adults with a BMI of 30 or above, or BMI of 27–29.9 with weight-related health conditions such as type 2 diabetes, high blood pressure, or cardiovascular disease. You can use our free BMI calculator above to check your current BMI and understand where you fall within NHS healthy weight guidelines.
Access routes include NHS specialist weight management services (tier 3) or private online prescribing through a UK-licensed prescriber. Mujaro is prescription-only — it requires a clinical assessment before being prescribed. Your GP or a prescriber will evaluate your individual health, medical history, and suitability. NHS access varies by region and waiting times can be lengthy, while private access is typically faster but involves a cost.
- 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 Mujaro the same as Ozempic?
No. Both contain semaglutide, but Ozempic is approved for type 2 diabetes (not weight loss), while Wegovy is the licensed weight management version. Mujaro is a different medication entirely — it's tirzepatide, a dual GIP/GLP-1 agonist, not a GLP-1-only medication.
How often do you inject Mujaro?
Mujaro is a once-weekly injection. You use a pre-filled KwikPen device. The starting dose is 2.5 mg, with gradual increases every 4 weeks up to a maximum of 15 mg weekly. Your prescriber will adjust the dose based on your response and tolerance.
What are the main side effects of Mujaro?
Common side effects include nausea, diarrhoea, vomiting, constipation, and stomach pain — especially during the first few weeks. Most side effects are mild and tend to improve over time. Serious side effects are rare but include severe stomach pain (possible pancreatitis) and allergic reactions — seek immediate medical attention if these occur.
Can I get Mujaro on the NHS in the UK?
Yes, Mujaro is available on the NHS through specialist tier 3 weight management services. However, access varies significantly by region (ICB), and waiting lists can be very long. Your GP can refer you if you meet eligibility criteria. Private access is also available without an NHS referral.
How much weight can I expect to lose with Mujaro?
Clinical trials showed average weight loss of 15–21% of body weight over 72 weeks alongside diet and exercise. However, individual results vary significantly — some people lose more, others less. Your own weight loss depends on your starting weight, how well you stick to lifestyle changes, and how your body responds to the medication.
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.