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?
Higher doses of Mounjaro (tirzepatide) do tend to support greater weight loss in clinical trials, but individual results vary significantly. Not everyone needs the maximum dose to achieve meaningful results, and higher doses come with increased side effects. Your prescriber will titrate your dose gradually based on your individual response and tolerance. Understanding how dose titration works is essential for realistic expectations about Mounjaro treatment in the UK.
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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 Mounjaro Dose Titration Works In The UK
Mounjaro is prescribed using a dose titration schedule, starting at the lowest dose and gradually increasing every 4 weeks. The standard titration pathway is: 2.5 mg (weeks 1–4), then 5 mg (weeks 5–8), then 7.5 mg (weeks 9–12), progressing up to the maximum of 15 mg once weekly. In clinical trials, participants on higher doses — particularly the 10 mg and 15 mg doses — achieved average weight loss of approximately 19.5% to 20.9% of body weight over 72 weeks, compared to around 15% on the 5 mg dose.
However, UK prescribers do not automatically escalate every patient to the maximum dose. Your GP or specialist will assess whether you need dose increases based on your weight loss progress, side effect tolerance, and overall health. Many patients achieve satisfactory results on 5 mg or 7.5 mg doses. The tirzepatide mechanism is optimised at lower doses for many people, and rushing to higher doses risks unnecessary side effects without proportional benefit.
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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.
Does Everyone Need The Maximum Mounjaro Dose?
No. The NHS does not recommend automatically escalating to 15 mg. Clinical response varies widely — some individuals lose significant weight on 5 mg, whilst others plateau and benefit from escalation. Your prescriber will monitor your progress and decide whether continuing at your current dose or increasing is appropriate for you.
Higher doses bring higher side effect burdens: nausea, diarrhoea, constipation, and vomiting are more common and more severe at 10 mg and 15 mg. If you are tolerating 7.5 mg well and losing weight steadily, your prescriber may recommend staying at that dose rather than pushing toward 15 mg. The goal is sustainable, tolerable weight loss alongside a reduced-calorie diet and increased physical activity — not achieving the highest dose possible. Use our GLP-1 weight loss calculator to explore realistic weight loss projections at different dose levels.
- 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.
Does higher Mounjaro dose always mean more weight loss?
Not always. Clinical trials show dose-dependent average weight loss, but individual response varies. Some people achieve good results on 5–7.5 mg and experience intolerable side effects at higher doses. Your prescriber tailors your dose to your personal tolerance and progress, not automatically to maximum.
What is the maximum Mounjaro dose in the UK?
The maximum approved dose is 15 mg once weekly (delivered via KwikPen). UK prescribers follow MHRA-approved titration schedules and do not exceed 15 mg. Most patients stabilise on 5–10 mg doses.
How long does it take to reach the maximum Mounjaro dose?
The standard titration takes approximately 20 weeks (5 weeks per dose increase: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, 15 mg). Your prescriber may pause or extend this if side effects occur or if you are achieving good results at a lower dose.
What are the side effects of higher Mounjaro doses?
Side effects — particularly nausea, diarrhoea, constipation, and stomach pain — are more common and more severe at higher doses (10 mg, 12.5 mg, 15 mg). Gastrointestinal effects typically settle over time, but some patients choose to remain on lower, better-tolerated doses.
Can I stay on a lower Mounjaro dose if I am losing weight?
Yes. Your UK prescriber will not escalate your dose if you are losing weight consistently and tolerating your current dose well. The goal is sustainable, manageable weight loss, not reaching the maximum dose. Discuss your progress and preferences with your prescriber at each review.
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.