Eating Meat From China And Mexico Could Result In Positive Test Results For Performance-Enhancing Drugs, NFL Warns Players

A new NFL memo is warning its players that meat produced in China and Mexico could potentially contain clenbuterol, a stimulant that is on the league's list of banned performance-enhancing drugs.

"Consuming large quantities of meat while visiting [China or Mexico] may result in a positive test," cautioned a notice from the NFL's independent drug-testing program. "Please take caution if you decide to consume meat, and understand that you do so at your own risk."

Though the substance is not licensed for use in meat-producing animals in the United States, the European Union, Mexico, and China, clenbuterol has been linked to a number of food poisoning outbreaks around the world, often as a result of the illegal use of the growth-promoting drug in livestock feed.

At least one player, Houston Texans left tackle Duane Brown, previously tested positive for clenbuterol, after having spent a week in Mexico and eating locally produced meat, sources told ESPN. It took months before Brown, who faced a 10-game suspension, was cleared to play.

"Players are responsible for what is in their bodies," the warning letter said in closing.