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 Come Off Mounjaro Without Gaining Weight
Stopping Mounjaro (tirzepatide) can mean weight regain without the right approach — but it's preventable with planning. Unlike stopping other medications, coming off a weekly weight loss injection requires a sustained shift back to independent calorie management, habit-building, and physical activity. This guide explains the rebound risk, safe tapering strategies, and practical steps to protect your progress when you decide to stop treatment.
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.
Understanding Weight Regain When Stopping Mounjaro
When you stop taking Mounjaro, your body no longer has the appetite-suppressing effects of the dual GIP and GLP-1 receptor agonist. Hunger signals return to baseline within days, which is why weight regain is common — not because of the medication itself, but because you must actively manage eating behaviour without pharmaceutical support.
Clinical context: Studies of GLP-1 medications show that most people regain 50–100% of lost weight within one year of stopping, unless lifestyle changes are maintained rigorously. This is not failure — it reflects the biological reality that weight regulation requires ongoing calorie control.
- Appetite returns to pre-treatment levels
- Satiety signals normalise within 7–14 days
- Basal metabolic rate may have adjusted downward during weight loss
- Habits formed during treatment must continue independently
Planning your exit strategy before stopping is essential. Many people who regain weight after stopping a weight loss injection simply didn't prepare for the transition back to self-managed appetite control.
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.
Safe Tapering and Transition Strategies
Unlike some medications, Mounjaro does not require a gradual taper — you can stop immediately without physical safety concerns. However, a behavioural taper is wise: reduce your dose (if your prescriber agrees) one or two steps before stopping entirely, using that time to strengthen eating and exercise habits.
Start preparing 4–8 weeks before your planned stop date. Use our free GLP-1 weight loss calculator to reset expectations for your new maintenance calorie needs. Begin keeping a food diary, increase structured exercise to at least 150 minutes weekly, and identify your personal hunger triggers. Work with your GP or a registered dietitian if available through NHS services — many integrated care boards now offer specialist weight management follow-up after stopping medication.
The most successful transitions involve replacing the medication's appetite control with structured routines: regular meal times, protein-rich breakfasts, planned snacks, and walking after meals.
- 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 much weight do people usually regain after stopping Mounjaro?
Evidence suggests most people regain 50–100% of their lost weight within 12 months if lifestyle changes aren't maintained. However, those who adopt sustained dietary and exercise habits often maintain 30–50% of their weight loss long-term. Individual results vary based on how strictly you maintain calorie deficit and exercise routine.
Can I reduce my Mounjaro dose gradually instead of stopping cold?
Yes — you can discuss a step-down with your prescriber (for example, moving from 15mg to 10mg for 4 weeks, then 5mg for 4 weeks before stopping). This isn't medically necessary but gives you time to adjust to appetite returning gradually and to solidify new eating habits before full medication withdrawal.
What's the best diet to prevent weight regain after stopping Mounjaro?
There's no single best diet. Evidence supports any approach you can sustain long-term: Mediterranean, low-calorie, or higher-protein all work if they maintain a modest calorie deficit. The key is consistency, not perfection. Use the BMI calculator and weight converter on this page to track your target maintenance range, and aim for the NHS recommendation of 0.5–1kg loss per week if still losing.
Should I switch to Wegovy instead of stopping completely?
Mounjaro and Wegovy are both GLP-1/GIP medications that work similarly — switching between them doesn't solve the underlying challenge of maintaining weight without medication. If you want to continue medication support, discuss this with your prescriber. If you want to stop, focus on the lifestyle foundation instead of switching injections.
What should I do if I start gaining weight after stopping Mounjaro?
Weight regain is expected; small amounts (1–2kg) in the first month are normal as your body retains water and your appetite normalises. If rapid regain occurs (3kg+ in 2 weeks), review your food intake and exercise. Consider speaking to your GP about NHS tier 2 or tier 3 weight management services for structured support, or ask about restarting medication if appropriate for your health.
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.