The Food and Drug Administration is warning to consumers not to buy dietary supplements containing the ingredient dimethylamylamine, or DMAA.
The strongly worded warning from the agency, which calls the DMAA illegal, is the first to explicitly caution consumers about the ingredient, experts say.
DMAA, most commonly found in supplements promoted for helping muscle-building and weight loss, can increase blood pressure, and may cause shortness of breath, irregular heartbeat and heart attacks, the FDA says.
The warning comes after the FDA sent letters to 11 companies last year, asking them to stop making and selling products containing DMAA. Since then, all but one of the companies has complied, the FDA said.
The FDA has received 60 reports of illnesses and deaths linked to supplements containing DMAA, although these reports cannot prove that the supplements were the cause of the health problems, the agency said.
Unlike medical drugs and devices, dietary supplements do not require FDA approval before they are sold to consumers. (Companies that sell supplements to not need to provide proof of their safety and efficacy.) The FDA regulates supplements only after they enter the market, and must undertake lengthy steps to remove a product it deems unsafe, the FDA said.