# GLP-1 drugs show anti-aging effects but side effects remain unclear > Weight-loss drugs reduce biological age markers, but researchers are still discovering unexpected effects on hair, nails, vision and more. - Title: GLP-1 drugs show anti-aging effects but side effects remain… - Summary: Weight-loss drugs reduce biological age markers, but researchers are still discovering unexpected effects on hair, nails, vision and more. GLP-1 weight-loss… - Keywords: glp-1 drugs, weight loss, side effects, biological aging, eli lilly, novo nordisk, hair loss, nail disorders, vision loss, pediatric use, technology, science - Source: MIT Technology Review — https://technologyreview.com/2026/10/09/1146094/were-still-figuring-out-the-side-effects-of-glp-1-weight-loss-drugs - Read time: 2 min - Topics: glp-1 drugs, weight loss, side effects, biological aging, eli lilly, novo nordisk, hair loss, nail disorders, vision loss, pediatric use, technology, science ## GLP-1 drugs show anti-aging effect Research presented at an aging meeting in Boston found that overweight and diabetic people taking GLP-1s have biological age around two to three years younger than those taking placebo. > biological age around two to three years younger than similar individuals who take a placebo ## GLP-1 use surging in America According to a recent Gallup poll, eleven percent of Americans are taking a GLP-1 drug for weight loss, up from three percent in twenty twenty-four. Fifteen percent say they have used one at some point. > 11% of Americans are taking a GLP-1 drug for weight loss, up from 3% in 2024 ## Approved uses expanding beyond diabetes GLP-1 agonist drugs are approved for treating diabetes, chronic kidney disease, and obesity. Research suggests they might also help people with substance-use disorders and have been investigated for neurodegenerative disease and cancer. ## Common gastrointestinal side effects The most common side effects are gastrointestinal: nausea, vomiting, diarrhea, and constipation. The drugs have also been linked to pancreatitis and gallstone disease. ## Vision loss lawsuits filed against makers Dozens of people are suing Novo Nordisk and Eli Lilly after developing a condition that can lead to sudden vision loss, claiming GLP-1 drugs caused their symptoms.Both companies dispute the claims. ## Hair loss and nail disorders emerging Research from George Washington University found GLP-1 use associated with increased hair loss risk. A separate study presented in Austria found sixty-six percent of GLP-1 users reported at least one nail disorder, though nail conditions… > 66% of GLP-1 users reported at least one nail disorder ## Pediatric prescriptions rising rapidly Between twenty nineteen and twenty twenty-six, there was a three hundred ten-fold increase in GLP-1 prescriptions for eight to eleven-year-old children with obesity in the US. Child prescriptions remain rare but are rising. > 310-fold increase in GLP-1 prescriptions for eight- to 11-year-old children ## WHO advises against drugs for young children The World Health Organization released its first obesity guidelines for children and adolescents, explicitly recommending against pharmacological treatment for kids under ten due to lack of evidence on benefits and potential adverse effects on growth… > does not recommend pharmacological treatment for kids under 10 ## Key takeaway GLP-1 weight-loss drugs show signs of slowing biological aging, but scientists are still identifying side effects including hair loss, nail disorders, and potential vision damage.