Prior to the 2009 season, Romero was suspended 50 games for testing positive for androstenedione, a performance-enhancing drug banned by MLB. Romero said that he bought a supplement named 6-OXO Extreme from a GNC store at the Cherry Hill Mall in Cherry Hill, New Jersey and that he was cleared to take it by two nutritionists. Romero actually tested positive on August 26, 2008, but he took the case to arbitration, allowing him to pitch in the postseason and World Series; after he stopped taking the supplement, he tested negative before the playoffs. Due to the suspension, Romero lost $1.25 million, so he is suing the makers of the supplement, Ergopharm Inc., along with The Vitamin Shoppe and GNC for his lost salary and punitive damages. Following the 50-game suspension, Romero returned to the Phillies' AAA affiliate, the Lehigh Valley IronPigs in May 2009. Romero returned to the Phillies on June 3, 2009.