Vijay Singh admitted to using deer antler spray, a "supplement" containing the banned substance IGF-1. But deer antler spray is so ineffective at delivering IGF-1 that the PGA tour has decided not to punish him. This is almost more embarrassing for Singh: he may not be suspended, but he did get scammed.
You do remember deer antler spray, right? Sports Illustrated did a whole blowout on the "scandal," and stupidly, it became the main story of Super Bowl week since Ray Lewis was accused of using it. But the SI story was a remarkable reach that failed at both science and reporting: the growth hormone IGF-1 cannot be delivered orally. SI's story implicated no one, and served as a massive press release for the spray's manufacturer, a half-crazy, self-promoting huckster named Mitch Ross. (With the publicity, the spray flew off the shelves.)