Weight back after GLP‑1s

Glucagon-like peptide 1 drugs help people lose weight by cutting appetite and slowing stomach emptying, but trials show many regain weight after stopping them. (who.int) In the STEP 1 trial, adults without diabetes who took semaglutide 2.4 milligrams weekly lost an average 14.9% of body weight at 68 weeks, versus 2.4% with placebo. (nejm.org) A second semaglutide study, STEP 4, put everyone on the drug for 20 weeks and then switched some to placebo; those who stayed on semaglutide kept losing weight, while those switched off regained weight over the next 48 weeks. (jamanetwork.com) Tirzepatide, a related obesity drug that also targets glucose-dependent insulinotropic polypeptide, showed the same pattern in SURMOUNT-4. After a 36-week lead-in, participants switched to placebo regained 14% of body weight by week 88, while those who stayed on tirzepatide lost another 5.5%. (jamanetwork.com) That rebound fits how obesity is now described in medical guidance: a chronic, relapsing disease rather than a short-term problem solved by a single round of treatment. The World Health Organization said in December 2025 that semaglutide, tirzepatide, and liraglutide may be used for long-term obesity treatment in adults. (who.int) The National Institute of Diabetes and Digestive and Kidney Diseases also treats obesity as a disease tied to diabetes, fatty liver disease, and heart risk, not just body size. Its 2025 obesity research agenda highlighted the problem of maintaining health gains after successful drug treatment. (niddk.nih.gov, niddk.nih.gov) Stopping is common. A 2024 JAMA commentary said real-world estimates put glucagon-like peptide 1 drug discontinuation at 50% to 75% within 12 months, even though trials show weight regain and worsening cardiometabolic markers after withdrawal. (jamanetwork.com) Researchers are now trying to separate how much regain comes from biology and how much from the way treatment ends. A 2026 Lancet eClinicalMedicine review of 37 studies reported that weight regain after stopping glucagon-like peptide 1 receptor agonists was common across trials, with larger losses on treatment often followed by larger rebounds off treatment. (thelancet.com) Some early data suggest people who combine medication with structured lifestyle programs may regain less after discontinuation, but those findings are still limited and do not erase the rebound seen in randomized withdrawal trials. (diabetesjournals.org, jamanetwork.com) The practical question has shifted from how fast these drugs lower weight to what happens when treatment changes. For patients who reach a goal weight, the evidence points less to an endpoint than to a maintenance plan. (who.int, jamanetwork.com)