Novo Nordisk’s Ozempic, Wegovy, and Rybelsus are all part of the same category of drugs called semaglutides, which originally were developed to treat type 2 diabetes—in part by helping people shed pounds better than any previous medication and therefore control their blood sugar. But it wasn’t until recently that their weight-loss feature propelled them to be among the most in-demand prescription medications. Still, the drugs aren’t without controversy over inappropriate use and side effects, including stomach and intestinal issues, that have prompted a warning from the FDA.