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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What Are The Maintenance Doses Of Mounjaro?
Mounjaro maintenance doses range from 5 mg to 15 mg once weekly, depending on individual response and tolerability. The maintenance phase typically begins after the initial dose titration schedule, usually around week 4–5. Understanding how Mounjaro maintenance compares to other weight management injections like Wegovy can help you and your GP make informed decisions about which prescription medication may be right for you.
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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.
Mounjaro Maintenance Doses vs Wegovy — Clinical Context
Mounjaro (tirzepatide) maintenance doses are: 5 mg, 7.5 mg, 10 mg, 12.5 mg, or 15 mg — each injected once weekly. The starting dose is 2.5 mg for weeks 1–4, then the dose is increased every 4 weeks until an effective maintenance dose is reached. Most patients maintain on 10 mg or 15 mg.
Wegovy (semaglutide) reaches maintenance at 2.4 mg once weekly — a single fixed dose. The titration takes longer (17+ weeks to reach 2.4 mg), starting at 0.25 mg.
Clinical trials showed differences: SURMOUNT-1 (Mounjaro) demonstrated approximately 20.9% average weight loss at 15 mg over 72 weeks, whilst STEP-1 (Wegovy) showed approximately 14.9% average weight loss at 2.4 mg over 68 weeks. However, individual results vary significantly, and both are GLP-1 pathway medications — Mounjaro uses a dual GIP+GLP-1 mechanism, whilst Wegovy uses GLP-1 only.
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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.
Which Maintenance Dose Is Right For You?
Your prescriber will assess which maintenance dose is appropriate based on your response during titration, tolerability of side effects, and individual health factors. Not everyone reaches the maximum dose — some patients find effective results at lower maintenance doses with fewer side effects.
Both Mounjaro and Wegovy require a UK prescription and clinical assessment from a licensed healthcare professional. Access is available through NHS specialist weight management services or private prescribing following an online consultation. Use our free GLP-1 weight loss calculator to explore potential outcomes at different doses, and our BMI calculator to assess your current health status before discussing prescription options with your GP.
- 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.
What is the difference between Mounjaro and Wegovy maintenance doses?
Mounjaro has multiple maintenance dose options (5–15 mg weekly), whilst Wegovy has a single maintenance dose of 2.4 mg weekly. Mounjaro's dual GIP+GLP-1 mechanism may explain why it has more dose steps. Both require personalised prescriber assessment to determine the right dose for you.
How long does it take to reach Mounjaro maintenance dose?
Mounjaro reaches maintenance typically around week 4–5 (at 5 mg), though many patients continue titration to higher doses. Each dose increase occurs every 4 weeks minimum. Full titration to 15 mg can take 20+ weeks. Your prescriber will guide your individual titration schedule.
Can you stay on a lower Mounjaro maintenance dose?
Yes. Some patients achieve effective weight loss and feel better on 5 mg, 7.5 mg, or 10 mg rather than the maximum 15 mg dose. Your prescriber will determine the right balance between efficacy and tolerability for your situation.
Is Mounjaro available on the NHS in the UK?
NICE has approved tirzepatide (Mounjaro) for NHS use, but access is through specialist tier 3/4 weight management services, not standard GP prescription. Regional availability varies significantly. Private prescription through GPhC-registered online pharmacies is also available.
How does Mounjaro's dose titration compare to Wegovy?
Mounjaro increases every 4 weeks starting at 2.5 mg, reaching maintenance at 5 mg (week 5). Wegovy increases every 4 weeks starting at 0.25 mg, reaching maintenance at 2.4 mg (week 17). Mounjaro's titration is faster due to its larger dose steps and dual mechanism.
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.