Marion Jones and the BALCO scandal threatened the fair play that undergirds the Olympic movement, leading the International Olympic Committee to adopt an antidoping regime that remains the world's standard. Baseball's "juiced-ball" era made a sham of the record books and led baseball writers in January to elect no players to the Hall of Fame; in the wake of such embarrassments, baseball is taking halting steps toward expanding its antidoping regime.
"In sports where comprehensive, unannounced testing is done year round, the sport is pretty clean and much, much better than, say, in the 1990s," says Jim Stray-Gundersen, an anti-doping expert who served as a physician for the 1988 and 1992 Olympic teams, in an e-mail. "In sports where there is not a comprehensive program, doping is likely as common as ever."
That leaves the National Football League (NFL) as the leading pariah of the antidoping world, with many experts saying that its first big PED scandal is more a matter of when, not if.
For much of the past three decades, Don Catlin has been on the front lines of the campaign against PEDs. The lab where he used to work, the UCLA Olympic Analytical Laboratory, was the first of its kind when it was founded in 1982. In it, he and his team developed a wide range of tests for PEDs including anabolic steroids, EPO (erythropoietin), and tetrahydrogestrinone (known as THG or "the clear" – the drug at the center of the BALCO scandal).
"Things are moving forward. But they're also stepping back," he says.
In particular, Armstrong's doping program, revealed in an October report by the United States Anti-Doping Agency (USADA), gives Mr. Catlin pause. While scientists are better than ever at identifying banned substances, athletes still can game the system.