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
Can You Stop Mounjaro After Losing Weight?
Yes, you can stop Mounjaro after reaching your weight loss goal — but it requires careful planning with your prescriber. Unlike some medications, Mounjaro is not a long-term treatment you must stay on forever. However, stopping suddenly can lead to weight regain. This guide explains how NHS and private prescribers approach discontinuation, what happens when you stop, and how to maintain weight loss after stopping this weekly weight loss injection.
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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.
What Happens When You Stop Mounjaro?
When you stop Mounjaro (tirzepatide), the medication leaves your system within approximately 7–10 days. As the GIP and GLP-1 receptor agonist effects wear off, your appetite-regulating mechanisms gradually return to their baseline state. This means hunger signals and food cravings typically increase within 1–2 weeks of stopping.
- Weight regain is common if diet and exercise habits don't remain consistent — clinical trial data suggests many people regain 30–50% of lost weight within 1–2 years if lifestyle changes aren't maintained
- Your prescriber may recommend a tapering schedule rather than stopping abruptly, though evidence for this is limited
- Some people find that the appetite-control skills and eating habits they developed while on Mounjaro help them maintain weight without the injection
Talk to your GP or prescriber about your specific situation — they can advise whether gradual reduction or immediate discontinuation is safer for you, especially if you have type 2 diabetes or prediabetes.
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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 Guidance and Managing Discontinuation
NICE and NHS guidance emphasises that weight loss medications like Mounjaro should be part of a broader lifestyle programme, not a standalone treatment. Most NHS specialist tier 3 weight management services will discuss your discontinuation plan from the outset — ideally working towards a point where you can maintain weight loss through diet and physical activity alone.
- Your NHS prescriber will typically review your progress every 4–12 weeks and discuss whether to continue, adjust dose, or plan a discontinuation date
- If you regain weight after stopping, you may be eligible to restart Mounjaro — discuss this with your GP or specialist
- Use our free GLP-1 weight loss calculator and progress tracker to monitor your journey and identify what lifestyle changes have worked for you
The goal is sustainable weight management, not indefinite medication use.
- 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 just stop taking Mounjaro whenever I want?
Technically yes — Mounjaro is not habit-forming and won't cause physical withdrawal. However, stopping abruptly without a plan typically leads to rapid weight regain. Your prescriber will recommend discontinuing gradually or at a planned time, alongside a solid plan for maintaining diet and exercise changes you've made.
How much weight do people regain after stopping Mounjaro?
Clinical trials show highly variable outcomes. Some people maintain most of their weight loss; others regain 30–50% within 1–2 years if they return to previous eating patterns. Success depends heavily on whether the lifestyle changes (diet, activity) developed during treatment are maintained long-term.
Will my GP help me plan to stop Mounjaro?
Yes — whether through NHS specialist services or private prescribing, your prescriber should discuss discontinuation planning. They'll advise on timing, whether to taper the dose, and what support you need to maintain weight loss through diet and exercise after stopping.
What should I do to prepare for stopping Mounjaro?
Work with your prescriber on a timeline, strengthen your diet and exercise habits while still taking it, plan your meals for after stopping, and consider using tools like our free progress tracker to identify what changes have worked best for you. Some people benefit from continued support from a dietitian.
Can I restart Mounjaro if I regain weight after stopping?
In many cases, yes — but eligibility depends on your BMI, health conditions, and whether you still meet NICE criteria. Discuss this with your GP or specialist. Restarting is generally considered if weight regain leads to return of weight-related health problems, not purely for cosmetic reasons.
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.