Who would have thought that a little echinacea could jeopardize an Olympic career? A survey of dietary supplements by a commission of the International Olympic Committee found banned performance-enhancers in 40 of 200 dietary supplements tested, none of which were listed on the label.

In response, the United States Anti-Doping Agency (USADA), a regulatory board of the United States Olympic Committee, warned athletes to avoid all dietary supplements because of what it called “lax governmental regulation and uneven manufacturing processes.” According to the USADA, their drug-testing labs can detect banned substances–such as steroids and their precursors, and performance-enhancers like ephedra, ma huang and guarana–in much smaller traces than tests used by the Food and Drug Administration. The USADA maintains that until the purity of supplements can be proven, athletes who choose to take them do so at their own risk.