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
How to Keep Weight Off After Mounjaro
Stopping Mounjaro doesn't mean weight inevitably returns. Research shows that maintaining the healthy habits developed during treatment—combined with a structured approach to managing appetite and lifestyle—can help keep weight off long-term. The NHS emphasises that Mounjaro is a tool to support behaviour change, not a permanent solution, which means the skills and routines you build while on treatment are what sustain results afterwards. This guide covers evidence-based strategies for weight maintenance after your treatment ends, helping you transition confidently to long-term weight management.
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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 taking Mounjaro (tirzepatide), your body gradually loses the appetite-suppressing effects within one to two weeks. Some people regain weight quickly without active management strategies, while others maintain loss successfully. Clinical experience suggests that weight regain is not inevitable—it depends on whether the behavioural changes made during treatment persist.
During Mounjaro therapy, you've likely developed new eating patterns, portion awareness, and possibly increased physical activity. These learned behaviours are the real foundation of sustained weight management. The GLP-1/GIP pathways that Mounjaro activates normalise over time after stopping, meaning your appetite regulation returns closer to baseline. This is why a transition plan is essential.
- Appetite signals will gradually re-emerge—expect this as normal, not failure
- Weight loss achieved on Mounjaro is real and sustainable if lifestyle foundations remain in place
- Most NHS guidance supports gradually rebuilding normal eating rather than sudden restriction
- Regular monitoring with your GP helps catch early weight regain and adjust strategy
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.
Building Long-Term Weight Maintenance Habits
Structured transition is more effective than abrupt stopping. Work with your GP or an NHS tier 3 weight management service to develop a tapering plan and post-treatment strategy. Key maintenance pillars include: consistent physical activity (150 minutes moderate activity weekly, per NHS guidance), mindful eating practices learned during treatment, and regular self-monitoring using tools like a progress tracker to catch early weight regain before it compounds.
Evidence shows that people who maintain weight loss typically combine ongoing dietary awareness, regular physical activity, and periodic check-ins with healthcare professionals. You may choose to transition to a weekly weight loss injection alternative like Wegovy, or manage through lifestyle alone—both are valid paths. Your prescriber can assess which approach suits your individual circumstances and health goals.
- 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 when I stop Mounjaro?
No. Weight regain is not inevitable. People who maintain the eating habits and physical activity patterns developed during Mounjaro treatment often sustain their weight loss long-term. However, without active management, some weight regain is common. Your outcome depends on the durability of behavioural changes you've made.
How quickly will appetite return after stopping Mounjaro?
Appetite-suppressing effects typically fade within one to two weeks of your last dose. You may notice increased hunger and food cravings returning gradually. This is a normal physiological response and does not mean treatment failed—it's an expected transition point where your maintenance strategy becomes crucial.
Can I switch to Wegovy instead of stopping treatment completely?
Yes. Wegovy (semaglutide) is another once-weekly weight loss injection licensed in the UK. Some people transition between GLP-1/GIP medications to maintain loss. This is a decision to make with your prescriber, who will assess whether continued medication aligns with your health needs and NHS/private access options.
What role does my GP play in weight maintenance after Mounjaro?
Your GP can monitor your progress through regular appointments, provide motivation and accountability, refer you back to NHS tier 3 services if needed, and help you manage any weight regain early. NHS guidance supports ongoing primary care involvement in weight management—don't hesitate to book check-ups regularly.
How can I track my weight loss progress after treatment ends?
Use a progress tracker to log your weight weekly and identify patterns. Our free progress tracker on MyWeightCheck helps you visualise trends and stay accountable. Regular self-monitoring (weekly rather than daily) is associated with better long-term maintenance in research.
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.