A class of medications developed to suppress appetite and address obesity has experienced swift adoption in the United States, though their long-term consequences, particularly for hair, nails, and eyesight, remain uncertain.
GLP-1 receptor agonists, initially approved for diabetes, chronic kidney disease, and obesity, have shown promise in treating substance-use disorders, neurodegenerative conditions, and even certain cancers. However, their widespread use has also revealed unintended consequences.
Adoption rates have climbed sharply: currently, 11% of Americans use these drugs for weight management, up from 3% in 2024, while 15% have tried them at some point. Though effective, they carry risks that are still being documented.
Digestive problems, nausea, vomiting, diarrhea, and constipation, are the most frequently reported side effects. Some users have developed pancreatitis or gallstones. A more alarming concern involves rare cases of optic nerve damage, prompting lawsuits against manufacturers Novo Nordisk and Eli Lilly. Plaintiffs allege the medications caused sudden vision loss, though both companies reject liability. Scientific evidence on the connection remains unresolved.
Hair loss has also surfaced as a possible side effect. A review of electronic health records from 67 U.S. healthcare systems found an association between GLP-1 use and increased hair loss risk, though the scale of the issue is still unclear. At a recent medical conference in Austria, researchers noted that 66% of GLP-1 users reported at least one nail disorder, including detachment in some cases. However, similar nail problems were observed in non-users, leaving causality in question.
Children represent another area of uncertainty. Prescriptions for GLP-1 drugs among 8- to 11-year-olds with obesity surged 310 times between 2019 and 2026, though overall use remains limited. The World Health Organization recently advised against pharmacological treatment for children under 10, citing insufficient data on safety, developmental impacts, and mental health risks.
Most clinical research centers on adults, leaving pediatric risks largely unexplored. The absence of long-term data, especially for younger patients, exposes a critical gap in understanding how these drugs affect growing bodies.
As studies progress, the rapid rise in GLP-1 prescriptions means some side effects may take years to fully emerge. While their benefits are well-established, the full scope of their risks, particularly for vulnerable populations, continues to evolve.
