KeptGLP-1 weight regain calculator
See what the big studies found after people stopped a GLP-1, applied to your numbers, and how soon a small drift would show up on the scale.
Enter both weights to see the numbers.
- Trial average for your medicine
- Pooled average, 37 studies
- Kept's early-warning line (+3.3 lb, 1.5 kg)
How the numbers are worked out
- Semaglutide: the STEP 1 extension found people regained about two-thirds of their lost weight in the year after stopping.
- Tirzepatide: in SURMOUNT-4, people switched to placebo regained 14% of their body weight over 52 weeks (never more than they lost, here).
- Other or not sure, and the pooled line: a 2026 BMJ review of 37 studies found an average regain of about 0.4 kg (0.9 lb) a month.
- Early-warning line: Kept nudges you when your 7-day average is 3.3 lb (1.5 kg) above your lowest weekly average.
These are group averages from people who stopped with nothing in place of the medicine. Many did much better: in SURMOUNT-4, about 46% of the placebo group still kept at least a 10% loss. The point of the calculator isn't the 12-month number. It's how early the drift crosses a few pounds, while one small change still fixes it. Our guide on keeping weight off after a GLP-1 covers what to do at that point.
Common questions
How much weight will I regain after stopping a GLP-1?
Nobody can predict it for one person. On average, people in the STEP 1 extension regained about two-thirds of their lost weight in the year after stopping semaglutide, and people in SURMOUNT-4 regained 14% of body weight in the year after stopping tirzepatide. Results ranged widely.
Is this calculator a prediction?
No. It shows the average path trial participants followed when nothing replaced the medicine. It's a way to see the scale of the risk and how early a small drift appears, not a forecast for you.
How do I avoid regaining weight after a GLP-1?
Weigh most mornings and watch your 7-day average, set a gain line in advance, plan for food noise, keep protein and strength training in your week and act with one small change as soon as you cross your line.
Sources
- Wilding JPH et al. Weight regain and cardiometabolic effects after withdrawal of semaglutide: the STEP 1 trial extension. Diabetes, Obesity and Metabolism, 2022. Link
- Aronne LJ et al. Continued treatment with tirzepatide for maintenance of weight reduction in adults with obesity (SURMOUNT-4). JAMA, 2024. Link
- West S et al. Weight regain after cessation of medication for weight management: systematic review and meta-analysis. BMJ, 2026;392:e085304. Link