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 Dosing Schedule
Mounjaro (tirzepatide) is a prescription-only, once-weekly injection for weight management in UK adults. This dose chart outlines the standard escalation schedule from the starting 2.5 mg dose through to the maximum 15 mg maintenance dose. Each dose is typically continued for four weeks before moving to the next level, though your prescriber may adjust this based on your individual response and tolerance. Understanding the dose progression can help you know what to expect as your treatment advances.
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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.
Standard Mounjaro Dose Escalation Schedule
Mounjaro uses a gradual escalation approach to find your optimal dose whilst minimising side effects. The standard UK dosing schedule is:
- Weeks 1–4: 2.5 mg (starting dose)
- Weeks 5–8: 5 mg (first escalation)
- Weeks 9–12: 7.5 mg
- Weeks 13–16: 10 mg
- Weeks 17–20: 12.5 mg
- Week 21 onwards: 15 mg (maximum dose)
Each injection is one dose per week. A single KwikPen contains four doses (four weeks' supply). Your prescriber may recommend staying at a particular dose longer if you're experiencing significant side effects, or escalate more quickly if you're tolerating it well. The goal is to reach a dose that works effectively for you whilst remaining tolerable.
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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.
What Happens at Each Dose Level
At the starting 2.5 mg dose, most people experience modest appetite reduction. As doses increase to 5 mg and beyond, the effect typically strengthens. Clinical trials showed that higher doses (10–15 mg) produced greater average weight loss — approximately 19.5% body weight at 10 mg and 20.9% at 15 mg — though individual results vary significantly. Use our GLP-1 weight loss calculator above to estimate potential outcomes at different doses. Not everyone needs the maximum dose; some people achieve their goals at 5 mg or 7.5 mg and remain at that level long-term. Your prescriber will discuss which dose is right for you based on your response, tolerability, and health goals.
- 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 I skip dose escalations or stay on a lower dose?
Yes. Dose escalations are guidelines, not requirements. If you're tolerating a dose well and seeing good results, your prescriber may recommend staying at that level rather than continuing to escalate. The goal is finding the dose that works for your body, not necessarily reaching the maximum.
What if I experience side effects at a particular dose?
Side effects like nausea and stomach upset are common, especially when escalating. Inform your prescriber, as they may recommend staying at your current dose longer, reducing the dose, or pausing escalation. Most side effects improve over time as your body adjusts.
How long between dose increases?
The standard minimum is four weeks between doses. This allows your body to adjust and lets you assess how well you're tolerating and responding to each dose before moving higher. Your prescriber may recommend longer intervals if needed.
Is Mounjaro the same strength as Wegovy?
No. Mounjaro (tirzepatide) and Wegovy (semaglutide) are different medications with different mechanisms. Mounjaro is a dual GIP and GLP-1 agonist; Wegovy is GLP-1 only. Their dose ranges and escalation schedules are not directly comparable, though both are once-weekly injections.
What if I miss a dose?
If you miss a dose within four days, take it as soon as you remember and continue your normal schedule. If more than four days have passed, skip that dose and take your next injection on the regularly scheduled day. Never take a double 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.