GLP‑1s don’t help everyone
Clinical reporting estimates about 10–15% of people who try GLP‑1 weight‑loss drugs do not lose weight, even as separate studies suggest the medicines may still offer heart and sleep benefits for some users ( ). Clinicians are exploring combo treatments and precision‑nutrition or muscle‑preservation strategies for nonresponders rather than relying on single‑drug approaches ( ).
Glucagon-like peptide 1 drugs help many people lose weight, but a sizable minority do not get that result from the medicines alone. (pmc.ncbi.nlm.nih.gov) These drugs mimic gut hormones that lower appetite and slow stomach emptying, which can reduce calorie intake over time. In the 2021 STEP 1 trial, 86.4% of adults on semaglutide lost at least 5% of body weight by week 68, which means 13.6% did not reach that threshold. (nejm.org) Outside tightly controlled trials, the spread can be wider. A 2025 retrospective cohort study of 483 adults in a Vancouver obesity clinic classified 17.8% of patients on semaglutide or liraglutide as nonresponders, defined as losing less than 5% of total body weight after follow-up averaging 17.3 months. (pmc.ncbi.nlm.nih.gov) The drugs can still improve health even when the scale moves less than patients expect. In the SELECT trial, semaglutide cut the rate of cardiovascular death, nonfatal heart attack, or nonfatal stroke to 6.5% from 8.0% over a mean 39.8 months in 17,604 adults with overweight or obesity and cardiovascular disease but no diabetes. (nejm.org) Sleep is another example. The Food and Drug Administration approved tirzepatide, sold as Zepbound, on December 20, 2024, for moderate to severe obstructive sleep apnea in adults with obesity after two randomized studies in 469 adults showed improvement in the condition. (fda.gov) Doctors are increasingly treating obesity as a chronic disease that may need more than one lever, not a single injection. A 2025 joint advisory from the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association, and the Obesity Society said real-world results are often lower than trial results and called for nutrition, strength training, body-composition checks, and screening for eating patterns and social barriers alongside drug treatment. (pmc.ncbi.nlm.nih.gov) That guidance also points to a newer concern: losing muscle along with fat. The advisory listed muscle and bone loss, gastrointestinal side effects, low long-term adherence, weight regain after stopping treatment, and high cost among the practical limits clinicians now have to manage. (pmc.ncbi.nlm.nih.gov) Researchers are still trying to sort out who responds best before treatment starts. The Vancouver study found female sex was associated with a higher chance of “hyper-response,” while age, diabetes status, baseline body mass index, sedentary behavior, anxiety, and depression were not independently linked to response in its multivariable analysis. (pmc.ncbi.nlm.nih.gov) The result is a more complicated message than the early hype around weight-loss shots. For patients who do not lose much weight, the next step is increasingly a more tailored plan around nutrition, exercise, body composition, and other health targets rather than assuming the drug has “failed.” (pmc.ncbi.nlm.nih.gov)
