Reliable information on serious side effects from supplements is hard to come by. Researchers at the Centers for Disease Control and Prevention and at the FDA studied emergency room records from 2004 through 2013 at 63 hospitals considered to be nationally representative. Based on 3,667 cases they found, they estimated there are about 23,000 ER visits each year for health problems related to supplements, and that about 2,154 lead to hospitalization.
Products for weight loss or increased energy accounted for the most ER visits. These products caused 72 percent of problems involving chest pain or irregular or too-fast heartbeats, and they were the culprits in more than half of visits among patients ages 5 to 34. Bodybuilding and sexual-enhancement products also led to cardiac symptoms in many seeking ER help.