Why GLP‑1s fail for ~10%
Researchers report a likely genetic reason some people respond poorly to GLP‑1 weight‑loss drugs and estimate about 10% of people may have a form of ‘GLP‑1 resistance.’ ( | ).
Glucagon-like peptide-1 drugs work by mimicking a gut hormone that helps control blood sugar and appetite, but a new Stanford-led study says about 10% of people carry gene variants that can blunt that signal. (news.stanford.edu) The study, published in *Genome Medicine* on April 10, traced that weaker response to variants in a gene called PAM, which helps activate hormones in the body, including glucagon-like peptide-1. Stanford said the decade-long project combined human experiments, mouse studies and data from diabetes drug trials. (news.stanford.edu) In trial data, carriers of those variants lowered blood glucose less effectively after six months on glucagon-like peptide-1 receptor agonists than non-carriers did, according to senior author Anna Gloyn of Stanford. The researchers said more than one in four people with Type 2 diabetes use this drug class. (news.stanford.edu) The key point is not that these patients make too little glucagon-like peptide-1. The Stanford team said variant carriers actually had higher hormone levels, but the hormone appeared less biologically effective, which is why the researchers used the term “glucagon-like peptide-1 resistance.” (sciencedaily.com) That finding helps explain a problem doctors have seen for years: two patients can take the same medicine and get very different results. Gloyn said knowing who is unlikely to respond could help doctors switch to a different diabetes treatment faster instead of waiting months to see poor control. (news.stanford.edu) The new paper was about blood sugar, not body weight. Stanford said it is still unclear whether the same PAM variants also reduce weight-loss results from higher-dose obesity drugs such as Ozempic and Wegovy. (news.stanford.edu) A separate paper in *Nature* on April 8 looked directly at obesity treatment and found genetic differences tied to how much weight people lose and whether they get nausea or vomiting on these drugs. That study analyzed 27,885 glucagon-like peptide-1 medication users and found one variant in the GLP1R gene linked to an extra 0.76 kilograms of weight loss per copy of the effect allele. (nature.com) That *Nature* study also found a side-effect signal in the GIPR gene that showed up only in people taking tirzepatide, sold as Mounjaro and Zepbound, and not in semaglutide users. The authors said those results could help sort patients by likely benefit and side-effect risk before treatment starts. (nature.com | mediacenter.23andme.com) Taken together, the two April 2026 studies point in the same direction: some “non-response” to glucagon-like peptide-1 drugs may be built into biology rather than caused by willpower, adherence or dosing alone. The next step is narrower medicine, with genetic testing used to predict who is likely to benefit before a prescription is written. (news.stanford.edu | nature.com)
