Recently, a large "Internet pharmacy" in Florida suspected of being a major supplier of illegal steroids and Human Growth Hormone (HGH) was raided and their records seized. A number of professional athletes were discovered in their customer lists.

According to SI.com, one name that has turned up is Kurt Angle, who "received two prescriptions for trenbolone and one for nandrolone between October 2004 and February '05." Angle's spokesman did not return messages seeking comment.

The whole article is here:

http://sportsillustrated.cnn.com/2007/more/03/06/rx.trouble0312/index.html

According to Wikipedia:

Trenbolone is a livestock steroid that has never been approved in any form for human consumption by the FDA, and in fact classifies as a Schedule III drug under the controlled substances act. It's used illicitly to increase muscle mass.

Nandrolone is a steroid with less side effects than most, and has some medical qualities approved for human use. It's still illegal without a legitimate prescription though.