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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How Much Does Mounjaro Dose Go Up By in the UK?
Mounjaro (tirzepatide) uses a gradual dose titration schedule in the UK, meaning your dose increases in steps over several months rather than starting at the maximum. Each step increases by specific amounts to allow your body to adjust and minimise side effects. Your prescriber will guide you through each increase based on your individual response and tolerance. Understanding this schedule helps you know what to expect during your weight management journey.
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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.
The Mounjaro UK Dose Titration Schedule
Mounjaro dose increases follow this standard UK titration schedule, with each dose held for a minimum of 4 weeks before escalating:
- Week 1–4: 2.5 mg — Starting dose for all patients. Allows your body to adjust to the medication.
- Week 5–8: 5 mg — First increase of 2.5 mg. Many patients remain at this dose long-term.
- Week 9–12: 7.5 mg — Second increase of 2.5 mg (cumulative: +5 mg from start).
- Week 13–16: 10 mg — Third increase of 2.5 mg.
- Week 17–20: 12.5 mg — Fourth increase of 2.5 mg.
- Week 21+: 15 mg — Maximum dose of 2.5 mg. This is the highest available dose in the UK.
Key point: You do not need to reach 15 mg. Your prescriber will recommend the dose that works best for your weight loss response and side effect tolerance. The dose increases by the same amount (2.5 mg) at each step, giving consistency and predictability.
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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.
Why Gradual Dose Increases Matter
Gradual titration reduces the risk of severe side effects like nausea and vomiting. Starting low allows your stomach and appetite regulation to adjust gently. If you experience intolerable side effects at any dose, your prescriber may keep you at that level longer or adjust your diet and hydration strategy. Each person responds differently — some patients find their optimal dose at 5 mg, whilst others benefit from higher doses. Clinical trials showed that weight loss continues to improve from 5 mg through to 15 mg, but individual results vary significantly. Use our free GLP-1 weight loss calculator to explore potential outcomes at different dose levels, and discuss your personal titration plan with your prescriber.
- 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.
Can my Mounjaro dose increase be skipped or delayed?
Yes. If you experience significant side effects, your prescriber can pause your dose increase. You may stay at your current dose for longer than 4 weeks, or your prescriber may recommend lifestyle adjustments before escalating. Never skip a dose yourself — always discuss any concerns with your prescriber.
What's the difference between Mounjaro and Wegovy dose increases?
Mounjaro increases by 2.5 mg weekly (starting 2.5 mg, maximum 15 mg). Wegovy increases by smaller amounts more gradually (starting 0.25 mg, maximum 2.4 mg) and takes longer to reach the top dose. Both use gradual titration but on different schedules. Mounjaro is a dual GIP + GLP-1 agonist; Wegovy is GLP-1 only.
How long does the full Mounjaro titration take in the UK?
The complete schedule from 2.5 mg to 15 mg takes approximately 20–21 weeks (about 5 months). However, most people remain at a lower dose long-term. Your prescriber will assess at each step whether to continue increasing or maintain your current dose based on effectiveness and tolerability.
Will I experience more side effects at higher Mounjaro doses?
Not necessarily. Side effects like nausea are most common when starting or increasing doses, then often improve as your body adjusts. Some people experience fewer side effects at higher doses if they've already adapted. Others prefer to stay at a lower dose where side effects are minimal. This is individual and requires discussion with your prescriber.
Is there a "best" Mounjaro dose for weight loss in the UK?
Clinical trials showed that weight loss improves progressively from 5 mg through 15 mg, but the difference between 10 mg and 15 mg is modest. The "best" dose is the one that gives you good weight loss results with side effects you can manage long-term. Many people stay at 5–10 mg successfully. Your prescriber will help you find your optimal 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.