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
What Happens When You Stop Taking Mounjaro?
If you've stopped taking Mounjaro (tirzepatide), you may have questions about weight regain, managing your health, and your next steps. Stopping this prescription injection can happen for various reasons — side effects, personal choice, or a change in circumstances. Understanding what to expect and how to maintain your progress is important. MyWeightCheck provides practical, evidence-based guidance to support your health journey after stopping treatment.
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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.
Weight Changes After Stopping Mounjaro
When you stop taking Mounjaro, your body's appetite regulation gradually returns to baseline over several weeks. Weight regain is common — clinical evidence suggests many people regain some weight after stopping GLP-1 or dual GIP/GLP-1 medications, though the amount varies significantly between individuals.
The timeline depends on several factors: how long you took Mounjaro, your current lifestyle, diet consistency, and physical activity levels. Some people maintain their weight loss through sustained behaviour change, whilst others experience gradual regain over weeks or months.
- Weeks 1–2: Appetite normalises, hunger signals return
- Weeks 2–4: Increased food intake may resume naturally
- Weeks 4–12: Weight regain typically becomes noticeable if lifestyle changes aren't maintained
The good news is that the healthy habits you developed whilst taking Mounjaro — reduced portion sizes, awareness of hunger cues, increased physical activity — can continue to support your weight management even after stopping.
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.
Maintaining Progress and Next Steps
To minimise weight regain after stopping Mounjaro, focus on the lifestyle foundations that made the injection effective: consistent calorie deficit, regular physical activity, and mindful eating patterns. Use our free weight converter to track your current weight in both kg and stone, then monitor your progress weekly using our free progress tracker.
If you've stopped due to side effects, speak with your GP about alternative options. If cost or access was the barrier, explore NHS specialist weight management services through your local integrated care board, or discuss private prescription options with a prescriber. Some people restart Mounjaro after a break; others find different approaches (dietary changes, increased exercise, or different medications like Wegovy) work better for their situation. Your GP can assess what's most suitable for your individual health needs and circumstances.
- 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.
Will I definitely regain weight if I stop taking Mounjaro?
No — weight regain varies. Some people maintain their loss through sustained lifestyle changes; others regain gradually. It depends on your diet consistency, physical activity, and how long you were on the medication. The habits you built whilst taking Mounjaro (portion control, awareness) can continue to help.
How quickly does weight come back after stopping?
Appetite typically normalises within 1–2 weeks. Noticeable weight regain usually begins around weeks 4–12, but the speed depends on your eating patterns and activity level. If you maintain a calorie deficit through diet and exercise, regain can be minimised significantly.
Can I restart Mounjaro if I stop now?
Yes — many people pause and restart Mounjaro for various reasons. Discuss with your prescriber or GP about whether restarting is appropriate for you. They'll assess your current health, reason for stopping, and any changes in your circumstances since you last took it.
What should I do if side effects made me stop?
Contact your GP or prescriber immediately. They can explore alternatives: adjusting your previous dose, switching to a different GLP-1 medication like Wegovy or Saxenda, or trying other weight management approaches. Side effects often improve with dose adjustment or time, and your prescriber can advise what's best.
Is it better to stop gradually or stop immediately?
Mounjaro doesn't require tapering — you can stop at any time without medical risk. However, appetite will return more noticeably if you stop abruptly. If you're concerned, discuss a gradual transition with your GP, perhaps by extending the time between injections slightly if your prescriber agrees.
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.