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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Mounjaro Dose Chart: Complete UK Prescribing Guide
Mounjaro (tirzepatide) is prescribed in the UK as a once-weekly injection following a gradual dose titration schedule. This guide explains the official UK dosing pathway, how long you stay on each dose, and what to expect at each stage. Whether you're accessing Mounjaro through NHS specialist services or private prescription, understanding the dose progression helps you know what happens next in your weight management journey. Use our free GLP-1 weight loss calculator to estimate potential results at different doses based on clinical trial data.
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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.
Mounjaro UK Dose Schedule and Titration Pathway
Mounjaro is prescribed in a stepwise titration schedule, with patients spending a minimum of 4 weeks on each dose before escalation:
- Weeks 1–4: 2.5 mg once weekly (starting dose for dose adjustment)
- Weeks 5–8: 5 mg once weekly (first maintenance dose)
- Weeks 9–12: 7.5 mg once weekly (escalation if needed)
- Weeks 13–16: 10 mg once weekly (escalation if needed)
- Weeks 17–20: 12.5 mg once weekly (escalation if needed)
- Week 21 onwards: 15 mg once weekly (maximum licensed dose)
Each Mounjaro KwikPen contains 4 weekly doses. Your prescriber will assess tolerability at each stage — if you experience significant side effects, you may remain on your current dose or dose escalation may be delayed. The dose titration aims to find the most effective dose with manageable side effects for your individual needs.
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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.
NHS Access, NICE Approval, and Private Prescribing Routes
Mounjaro is approved by NICE for use within NHS specialist tier 3 weight management services for adults with a BMI of 30 kg/m² or above, or BMI 27–29.9 with weight-related health conditions such as type 2 diabetes, hypertension, or cardiovascular disease. Access through the NHS requires GP referral to your local specialist weight management service, and availability varies significantly by region and current waiting lists. Alternatively, Mounjaro is available through private prescription following an online clinical assessment with a UK-licensed prescriber. Calculate your personal BMI using our free tool to check your eligibility range, and discuss your options with your GP or a qualified healthcare professional to determine the best prescribing route for you.
- 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.
How long does it take to reach the maximum Mounjaro dose?
The full titration pathway takes approximately 20–21 weeks to reach the maximum 15 mg dose, spending a minimum of 4 weeks on each dose step. However, many people benefit from remaining on lower doses (5–10 mg) and do not need to escalate to 15 mg. Your prescriber will personalise your dose based on clinical response and tolerability.
Can you skip Mounjaro doses during the titration?
No — the titration schedule is designed to allow your body to adjust gradually. Skipping doses or increasing too quickly increases the risk of severe side effects, particularly nausea and gastrointestinal symptoms. Always follow your prescriber's guidance on dose timing and escalation.
What's the difference between Mounjaro and Wegovy dose schedules?
Mounjaro uses larger doses (2.5–15 mg weekly) with 4-week intervals, while Wegovy uses smaller doses (0.25–2.4 mg weekly) with slightly longer escalation periods. Mounjaro is a dual GIP/GLP-1 agonist; Wegovy is GLP-1 only. The KwikPen delivery and once-weekly frequency are the same, but doses are not directly interchangeable.
Is there a standard dose that works best for weight loss?
Clinical trials showed that higher doses (10–15 mg of tirzepatide) produced greater average weight loss than lower doses, but individual response varies significantly. Many people lose meaningful weight at 5–10 mg. Your prescriber will assess your progress and adjust your dose based on your personal results and how well you tolerate each dose step.
What happens if Mounjaro side effects are severe at a particular dose?
If you experience severe side effects (persistent vomiting, severe nausea, or abdominal pain), inform your prescriber immediately. You may remain on your current dose for longer, return to a previous dose, or stop treatment. Never adjust your dose without medical guidance — side effects often improve over time as your body adjusts.
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.