Slugger Barry Bonds, sprinter Tim Montgomery and now Olympic gold medalist Marion Jones have admitted to taking a powerful anabolic steroid known as "the clear," and they all say they got it from the same place—the Bay Area Laboratory Co-Operative, or BALCO, whose founder, Victor Conte, served four months in prison. But the athletes have one more thing in common: they each claim they thought they were taking flaxseed oil. Could they all have made the same honest mistake? And what the heck is flaxseed oil anyway? "You'd have to be a moron to confuse flaxseed oil with an anabolic steroid," says Jose Antonio, head of the International Society of Sports Nutrition. Derived from crushed flax-plant seeds, flaxseed oil is primarily used as an over-the-counter nutritional supplement that helps with heart disease and menopausal symptoms. It's also a common wood finish. But will it help you run faster? "That's a big stretch," says Antonio. "There's no evidence it leads to performance benefits." But it's a nifty excuse for taking something that does.