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
Does a Higher Dose of Mounjaro Work Better?
Yes, clinical evidence suggests higher Mounjaro doses generally produce greater average weight loss, but individual results vary significantly. Mounjaro (tirzepatide) works through dose titration—starting at 2.5 mg and gradually increasing to a maximum of 15 mg. However, a higher dose doesn't automatically mean better results for everyone. The relationship between dose and weight loss is real, but effectiveness also depends on diet, exercise, medical history, and how your body responds. This guide explains how Mounjaro dosing works, what the clinical data shows, and how to access it through the NHS or privately in the UK.
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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.
Clinical Evidence: How Mounjaro Dose Affects Weight Loss
The SURMOUNT-1 clinical trial demonstrated a clear dose-response relationship for tirzepatide. At the 5 mg dose, participants lost an average of approximately 15% of their body weight over 72 weeks. At 10 mg, average weight loss increased to around 19.5%, and at the maximum 15 mg dose, participants achieved an average of clinically studied weight loss. However, these are clinical trial averages—individual results ranged widely, and some people at lower doses lost more weight than others at higher doses.
Factors affecting dose effectiveness:
- Adherence to reduced-calorie diet and exercise
- Starting weight and baseline metabolic rate
- Genetics and individual response to GLP-1/GIP agonists
- Other medications and health conditions
- Tolerance to gastrointestinal side effects
A higher dose may not produce better results if you're not maintaining the lifestyle changes that support weight loss. Mounjaro works alongside diet and physical activity, not instead of them.
Clinically BackedWeight Loss
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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.
Mounjaro Dosing, Cost, and UK Access
Dose titration schedule: Mounjaro starts at 2.5 mg weekly and increases every 4 weeks: 5 mg, 7.5 mg, 10 mg, 12.5 mg, and finally 15 mg. Your prescriber decides when—and whether—to increase based on your tolerability and response. Some people achieve good results at 5 or 10 mg and don't need escalation.
UK access routes: Through the NHS, Mounjaro is available via tier 3 specialist weight management services following GP referral, though availability and waiting times vary by region. Privately, it's available through GPhC-registered pharmacies following an online clinical assessment with a UK-licensed prescriber. Costs vary by dose (typically £129–£320 per month for private prescriptions). Try our free GLP-1 weight loss calculator to explore projected outcomes at different doses before starting.
- 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.
Will moving from 5 mg to 10 mg Mounjaro double my weight loss?
No. Clinical trials show weight loss increases from about 15% at 5 mg to 19.5% at 10 mg—a meaningful increase, but not a doubling. The gain diminishes at higher doses. Individual variation is significant; some people see major differences between doses, others see minimal change.
Can I stay on a lower Mounjaro dose if it's working well?
Yes. If you're losing weight steadily at 5 mg or 7.5 mg and tolerating it well, there's no requirement to escalate further. Your prescriber may recommend staying at an effective dose rather than chasing the maximum. The goal is sustainable weight loss with manageable side effects.
Does Mounjaro side effects get worse at higher doses?
Generally yes. Nausea, diarrhoea, and vomiting are more common and severe at higher doses, particularly 12.5 mg and 15 mg. Many people stay at 10 mg or below for this reason. Your prescriber will discuss whether dose escalation is appropriate for your health.
Is higher-dose Mounjaro more expensive on the NHS?
Mounjaro is dispensed as a KwikPen containing one week's dose. Regardless of dose strength, you typically get one pen per week. Private costs vary slightly by dose but are roughly similar across the dosing range. Ask your provider about your specific pricing.
How long does it take to reach the higher Mounjaro doses?
Minimum 20 weeks to reach 15 mg (4 weeks at each of five escalation steps: 2.5 mg → 5 mg → 7.5 mg → 10 mg → 12.5 mg → 15 mg). Your prescriber may pause or skip steps if you experience significant side effects or are responding well at a lower dose.
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.