Pettitte admitted he used human growth hormone but said it was to speed up recovery from injuries and not to get a competitive advantage.
"I never want a young person to do what I did," Pettitte told a news conference.
Pettitte apologized to the New York Yankees -- his current team -- and Houston Astros -- a former team -- "their fans, my teammates and all baseball fans for the embarrassment I have caused them."
"I also want to tell anyone who is an Andy Pettitte fan that I'm sorry," he said
Pettitte was one of the most high-profile players named in baseball's Mitchell report on performance-enhancing drug use in baseball. He's admitted to using HGH in 2002 and 2004 while recovering from elbow injuries. He said he knew it was in violation of MLB rules.
He also said "there are no other surprises out there" and another other drug-use rumors "would just be false allegations."