Home-run slugger Mark McGwire provoked controversy in summer 1998 when it was reported that he was using the supplement androstenedione. In his defense, there was a comment from the Cardinals' "medical staff" disputing that androstenedione is a steroid.

The NBA announced March 30, 2000 that it was adding the muscle-building supplement androstenedione and eight other performance-enhancing substances to its list of banned substances. But its players' union immediately filed a grievance, challenging the list's inclusion of andro and DHEA (dehydroepiandrosterone), a steroid hormone.

A commercial site that sells androstenedione describes its product line. Here is my translation of that information into chemical structures. Use them for drawing missing structures and practicing nomenclature.

If you conduct a web search on "androstenedione" you can receive ~5000 hits; almost all of them seem to be selling it. "Go ask Alice" is the only site I found (in the first 100 hits) which provided some balanced information.

Update, Jan., 2010: Mark McGuire admitted to using steroids off and on for nearly a decade and during the 1998 season. He says he used them only for "health purposes" and not for their performance-enhancing properties.

Update, Jan., 2013: Lance Armstrong has finally admitted to using a "cocktail" of banned substances, including testosterone, to boost his performance.