Everybody is guessing what O'Hearn is on, or is not and it's all pure conjecture. Maybe O'Hearn doesn't take anything. Who really knows?
I watched Ric Drasin interview old school body builder Steve Davis and he laid out what they took in the 70's and 80's and it was pretty minimal. They spent most of their time lifting heavy. Davis was very open. Here is the link:
http://youtu.be/31-kQbjtxDc?t=456 Given all the training knowledge these days, and how much they over trained back then, who is to say a genetic freak pops up now and then who actually doesn't use?
The only guy on here who seems to have a clue is Tommy Wishbone, but I don't recall him laying it out on GetBig.