Genes tweak GLP‑1 effects
Researchers found common variants in the GLP‑1 receptor gene that slightly increase weight loss on GLP‑1 drugs but also raise nausea and vomiting rates (social analysis of ~28,000 users). (x.com) The 23andMe‑linked analysis reported carriers lost about an extra 2–4 pounds on GLP‑1s while having a 57% higher risk of vomiting and 36% higher risk of nausea, and a separate GIPR variant was tied to an 83% higher vomiting risk specifically with tirzepatide. (pharmexec.com)
GLP-1 drugs copy gut hormones that slow stomach emptying and curb appetite, but people on the same shot often lose very different amounts of weight. A Nature study published April 8 found part of that gap tracks with inherited differences in the genes those drugs target. (nature.com) Researchers at the 23andMe Research Institute ran a genome-wide association study in 27,885 people who reported using semaglutide or tirzepatide. They linked self-reported weight loss and side effects to common variants in GLP1R, the gene for the glucagon-like peptide-1 receptor, and GIPR, the gene for the glucose-dependent insulinotropic polypeptide receptor. (nature.com) The clearest weight-loss signal came from a missense variant in GLP1R, a one-letter DNA change that alters the receptor protein. Each copy of that variant was tied to an extra 0.76 kilograms, or about 1.7 pounds, of weight loss over roughly eight months. (nature.com; sciencenews.org) People with two copies of that GLP1R variant lost about 1.5 kilograms, or 3.3 pounds, more than non-carriers in the 23andMe dataset. The same study linked variation in GLP1R to higher odds of nausea and vomiting, two of the most common reasons patients stop or scale back these drugs. (sciencenews.org; nature.com) A separate signal showed up in GIPR, but only in people taking tirzepatide, which hits both the GLP-1 and GIP pathways. PharmExec, citing the paper, reported that variant carried an 83% higher vomiting risk with tirzepatide and did not show the same effect with semaglutide. (pharmexec.com; 23andme.com) These medicines are now used far beyond diabetes care. Wegovy, the semaglutide obesity brand, carries a U.S. indication for chronic weight management and, since March 2024, for reducing major cardiovascular events in some adults with cardiovascular disease and overweight or obesity; Zepbound, the tirzepatide obesity brand, is approved for chronic weight management. (accessdata.fda.gov; fda.gov) The new paper does not say genes determine who will or will not benefit. The GLP1R effect explained only a slice of the variation, and 23andMe said its model worked best when genetic signals were combined with demographic and clinical factors. (nature.com; 23andme.com) Outside researchers told STAT the findings are biologically plausible because GLP1R is the direct drug target, but they questioned how quickly the results will change prescribing. The study relied on self-reported outcomes from 23andMe participants rather than randomized clinical testing. (statnews.com; nature.com) 23andMe has already turned the results into a consumer report for members of its Total Health service. For now, the paper offers a narrower claim: some common DNA variants appear to nudge both the payoff and the side effects of GLP-1 treatment, not rewrite them. (23andme.com; nature.com)
