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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Why You're Still Hungry on Mounjaro — What Might Be Happening
If you're on Mounjaro (tirzepatide) and still experiencing persistent hunger, you're not alone — and there are several reasons this might be happening. Mounjaro may help reduce appetite and support feeling fuller after eating, but it doesn't work the same way for everyone. Some people need dose adjustments, others may have timing or lifestyle factors affecting results, and in rare cases, the medication may not be the right choice for an individual. This guide explains what might be going on and what steps you can take with your prescriber.
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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.
Common Reasons Mounjaro May Not Be Suppressing Appetite Yet
Mounjaro's appetite-suppressing effects typically build over time as your dose increases through the titration schedule. If you're still hungry, consider these factors:
- You're on a low dose: Starting doses (2.5 mg) are designed to allow your body to adjust. You may not feel significant appetite reduction until you reach 5 mg or higher. Each dose is used for at least 4 weeks before escalating.
- It's early in treatment: Clinical trials showed appetite suppression increases as dosing progresses. If you've been on Mounjaro for only a few weeks, your body may still be adjusting.
- You're not in a calorie deficit: Mounjaro supports appetite reduction but works best alongside intentional dietary changes. Simply eating normally while on the injection may not create the calorie deficit needed for weight loss.
- Meal timing matters: Some people find eating smaller, more frequent meals helps; others do better with structured meal times. Experiment to see what works for your hunger patterns.
- Individual variation: Not everyone experiences the same appetite suppression. Some people respond very well; others see modest effects. Tirzepatide works on biological pathways that vary between individuals.
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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
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When to Talk to Your Prescriber About Persistent Hunger
If hunger remains a problem after 8–12 weeks on your current dose, contact your prescriber before your next dose increase. They can assess whether a dose escalation is appropriate, explore whether other factors (sleep, stress, medication timing) are affecting hunger, or discuss whether this medication is the best fit for you. Use our free GLP-1 weight loss calculator to track your progress and identify patterns — this information is valuable to share with your prescriber. Remember: Mounjaro is prescription-only and works best when combined with reduced-calorie eating and increased physical activity. Your prescriber can help personalise your treatment plan.
- 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 for Mounjaro to reduce hunger?
Appetite suppression typically increases as your dose escalates through the titration schedule over 16–20 weeks. Some people notice effects at 5 mg; others need higher doses. Individual variation is normal. If hunger isn't improving after 8–12 weeks, discuss with your prescriber.
Could something else be causing my continued hunger on Mounjaro?
Yes. Sleep deprivation, high stress, rapid eating, certain medications, and underlying medical conditions can all increase hunger signals. If you're on Mounjaro but not in a calorie deficit, eating normal portions won't create weight loss. Your GP can rule out medical factors.
Is Mounjaro the same as Wegovy?
No. Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist. Wegovy (semaglutide) is a GLP-1-only agonist. Both may help reduce appetite, but they work slightly differently. Your prescriber chose Mounjaro specifically for you based on your assessment.
Should I increase my Mounjaro dose if I'm still hungry?
Don't increase your dose on your own. Speak to your prescriber first. Dose increases follow a specific schedule (minimum 4 weeks per dose), and your prescriber will assess whether escalation is appropriate based on your progress and tolerability.
What if Mounjaro still doesn't work after reaching the maximum dose?
Some people experience modest appetite suppression rather than dramatic hunger reduction. If you've reached 15 mg (maximum) and results aren't meeting your goals, discuss alternative approaches with your prescriber — including whether a different medication or intensive lifestyle support might suit you better.
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.