New Muscle-Building Drugs at Risk of Being Abused, Experts Say

New drugs being tested as treatments for muscle-wasting diseases such as muscular dystrophy could be abused by athletes if they reach the market, experts tell NPR.

Researchers are also studying the drugs, called myostatin inhibitors, as potential treatments for muscle wasting in other diseases, such as cancer and kidney disease. The drugs block a substance called myostatin, which the body normally produces to stop muscles from becoming too large. At least one myostatin inhibitor is likely to receive approval by the Food and Drug Administration in the next few years, the article notes.

“When the myostatin inhibitors come along, they’ll be abused,” Carlon Colker, a physician and bodybuilder, told NPR. “There’s no question in my mind.” Leo Sweeney, who studies muscle diseases at the University of Pennsylvania, first warned about the potential abuse of myostatin in sports nearly a decade ago. He says the drugs will probably not leave any trace once someone stops taking them, making them difficult to detect.

Sweeney says he is concerned that if myostatin inhibitors become known as doping agents, doctors may hesitate to prescribe them for legitimate medical uses. “The sort of unmet need in all these diseases far outweighs whether somebody wins a bicycle race or a sprinting event because they cheated,” he says.

The World Anti-Doping Agency banned substances that inhibit myostatin in 2008.