This week my colleague Antonio Regalado had an interesting update on GLP-1 weight-loss drugs. According to research presented at an aging meeting in Boston, these drugs seem to affect at least some measures of biological age. Overweight and diabetic people who take GLP-1s have a biological age around two to three years younger than similar people who don't.
I've heard people in the aging field describe GLP-1s as longevity drugs for a while now, even if they only benefit people who are overweight or diabetic in the first place. This latest announcement comes after we've seen a raft of other benefits associated with taking these drugs. But there are also some weird side effects. GLP-1 agonist drugs, which repress hunger, have been approved for treating diabetes, chronic kidney disease, and obesity. There is also research suggesting they might help people with substance-use disorders, and they have been investigated for neurodegenerative disease and cancer.
A lot of people are taking them. According to a recent Gallup poll, 11% of Americans are taking a GLP-1 drug for weight loss, up from 3% in 2024. They can be incredibly effective, but like any drug, they can come with side effects, and we are still figuring out what those might be and how widespread they are. The most common are gastrointestinal: nausea, vomiting, diarrhea, and constipation. The drugs have also been linked to pancreatitis and gallstone disease. Dozens of people are suing Novo and Eli Lilly after developing a condition that can lead to sudden vision loss, claiming the GLP-1 drugs these companies manufacture caused their symptoms. Both companies dispute the claims, and research into the link is mixed.
Research on hair and nails is also still developing. A study led by Savanna Vidal at the George Washington University School of Medicine and Health Sciences found that GLP-1 use was associated with an increased risk of hair loss, though it is not thought to be common. A smaller study presented in Austria suggested that 66% of GLP-1 users reported at least one nail disorder, but nail conditions were also fairly common among people who didn't take the drugs. Pediatric side effects remain largely unstudied, even as GLP-1 prescriptions for eight- to 11-year-olds with obesity in the US rose 310-fold between 2019 and 2026. The World Health Organization recently said it does not recommend pharmacological treatment for children under 10, citing a lack of evidence on benefits and potential adverse effects.
Source: MIT Technology Review · Summarized by HeadlinesBriefing