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
Free tracker included with every download this week
Do You Have To Wean Off Mounjaro?
Stopping Mounjaro (tirzepatide) doesn't require gradual weaning in the way some medications do. You can stop at any dose without tapering down, though your prescriber may recommend a specific stopping approach based on your individual circumstances. Unlike some medications that need careful dose reduction, Mounjaro's once-weekly dosing schedule means you simply don't inject the following week. Understanding how to stop safely and what to expect afterwards is important for anyone considering ending this prescription-only weight management injection. Our free GLP-1 weight loss calculator can help you track your progress throughout your treatment journey.
10,000+ calculations today · NHS-aligned thresholds · 100% free
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 Stopping vs Wegovy — Key Differences
Mounjaro (tirzepatide) and Wegovy (semaglutide) both work as GLP-1 receptor agonists — though Mounjaro is technically a dual GIP and GLP-1 agonist. Neither medication requires a formal tapering schedule when stopping. You can discontinue Mounjaro immediately after your last injection without dose reduction. The main difference between the two lies in their mechanisms: Mounjaro activates both GIP and GLP-1 pathways, whilst Wegovy activates GLP-1 only. Clinical trials (SURMOUNT for Mounjaro, STEP for Wegovy) showed different average weight loss outcomes — Mounjaro approximately 15–21% body weight, Wegovy approximately 15% body weight — but individual results vary significantly. Both are prescription-only UK medicines requiring clinical assessment before starting. Your prescriber will advise on the best stopping approach for your personal situation, taking into account your health status and treatment goals.
Clinically BackedWeight Loss
No appointments. No waiting rooms. Just care — from a UK-regulated online pharmacy.
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 When You Stop — Expectations
After stopping Mounjaro, most people experience gradual changes over weeks to months rather than immediate effects. Appetite and hunger signals typically return as the medication leaves your system — this usually takes 4–5 weeks. Some people notice weight regain, whilst others maintain weight loss depending on whether they continue dietary and lifestyle changes. Nausea and gastrointestinal side effects resolve within a few weeks. There is no medical danger in stopping suddenly — your body will not experience rebound effects or withdrawal symptoms. However, discussing your stopping plan with your prescriber is essential. They may recommend either stopping immediately or finishing your current injection and not repeating it. If you've been using our free progress tracker during treatment, continuing to log your weight and wellbeing after stopping can help you notice patterns in appetite and weight changes.
- 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.
Do I need to taper Mounjaro like some other medications?
No. Mounjaro doesn't require tapering or gradual dose reduction. You can stop taking it immediately after your last injection without safety concerns. Your prescriber will confirm the best timing for your situation, but there is no medical requirement to wean off gradually.
What's the difference between Mounjaro and Wegovy stopping?
Both Mounjaro (tirzepatide) and Wegovy (semaglutide) can be stopped without tapering. The main difference is their mechanism: Mounjaro is a dual GIP+GLP-1 agonist, whilst Wegovy is GLP-1 only. Stopping procedures are virtually identical for both medications.
How long after stopping Mounjaro does hunger return?
Appetite typically returns gradually over 3–5 weeks as the medication clears your system. Most people notice increased hunger around week 2–3. The timeline varies between individuals depending on dose, body chemistry, and how long you were taking it.
Will I regain weight after stopping Mounjaro?
Weight regain depends entirely on your diet and activity level after stopping. Mounjaro doesn't prevent weight regain on its own — it works alongside reduced calories and activity. Many people maintain weight loss if they continue healthy habits; others regain weight if they return to previous eating patterns.
Should I talk to my GP before stopping Mounjaro?
Yes, absolutely. Your prescriber should confirm the best way to stop for you. Even though there's no medical danger in stopping immediately, your GP or the prescriber who issued your prescription should be informed and may want to discuss any support you need post-treatment.
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.