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 the Golden Dose for Mounjaro?
The "golden dose" for Mounjaro refers to the 10 mg weekly injection — often considered the optimal balance between effectiveness and side effects by people using tirzepatide. However, Mounjaro doses range from 2.5 mg to 15 mg, and the right dose for you depends on your individual health, tolerability, and response. This guide explains Mounjaro dosing, how to use your KwikPen, and what "golden dose" means in practice. Remember, only a licensed prescriber can determine the appropriate dose for your specific situation.
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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.
Understanding Mounjaro Dose Escalation and the "Golden Dose"
Mounjaro (tirzepatide) is a once-weekly prescription-only injection that comes in a KwikPen device. The standard dosing schedule starts at 2.5 mg and increases every four weeks: 2.5 mg → 5 mg → 7.5 mg → 10 mg → 12.5 mg → 15 mg. The term "golden dose" emerged informally among UK users to describe 10 mg — a dose many find delivers strong weight loss benefits while managing side effects reasonably well. However, clinical trial data (SURMOUNT-1) showed average weight loss of approximately 19.5% at 10 mg and 20.9% at 15 mg, meaning the maximum dose may produce better results for some individuals. Your prescriber will assess which dose is right for you based on your response, tolerability, and health goals. Never adjust your dose yourself — always follow your prescriber's guidance.
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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.
How to Use Your Mounjaro KwikPen and Progress Through Doses
Your Mounjaro arrives as a pre-filled KwikPen containing four weekly doses (one month's supply). Injection sites include your stomach (abdomen), upper thigh, or upper arm — rotate sites each week to prevent irritation. Store unopened pens in the fridge (2–8°C), but after first use can be kept at room temperature (below 30°C) for up to 30 days. Each pen is used once weekly, on the same day each week if possible. Common side effects like nausea and stomach discomfort often improve as your body adjusts, which is why gradual dose escalation is standard practice. Use our free weight loss calculator to project potential results at different Mounjaro doses and track your progress with our progress tracker.
- 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 does "golden dose" Mounjaro actually mean?
"Golden dose" is an informal term used by UK Mounjaro users to describe the 10 mg weekly dose — many find it balances strong weight loss results with manageable side effects. However, prescriber guidance is individual. Some people need lower doses due to side effects; others progress to 15 mg for maximum effect. Your prescriber will determine the best dose for you.
How long does it take to reach the 10 mg dose?
It takes approximately 20 weeks to reach 10 mg from the starting dose of 2.5 mg, as you increase by one step every four weeks (2.5 → 5 → 7.5 → 10 mg). This gradual escalation helps your body adjust and minimises side effects. Never skip steps or increase faster than prescribed.
Can I stay on 10 mg Mounjaro or do I have to go higher?
Yes, you can stay on 10 mg if it's working well for you and you're tolerating it. Your prescriber will assess your progress and side effect profile to decide whether to continue at 10 mg or escalate further. Individual weight loss varies, so the right dose is the one that works for your body and health.
What are the main side effects at higher Mounjaro doses?
Common side effects include nausea, vomiting, diarrhoea, constipation, and stomach pain — often worse when starting or increasing dose. These typically improve over two to four weeks as your body adapts. Serious side effects are rare but include severe stomach pain (possible pancreatitis) requiring urgent medical attention.
Is Mounjaro available on the NHS in the UK?
Mounjaro (tirzepatide) is NICE-approved for NHS specialist weight management services, but access varies significantly by region and waiting lists can be lengthy. Private prescription options are available through UK-licensed online prescribers following clinical assessment. Your GP can discuss both pathways with you.
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.