Detaching myself from the personal sideswipes, I guess the question should surround the "friends" ability to pilot an aicraft safely. I can only give my perspective as an expert in health care, not as an expert in aviation. There was a simillar thread dealling with these issues last xmas, but unfortunately it was deleted.
However, what I can say, is that in terms of risk, there is some evidence that taking anabolic steroids, could detrimentally affect this chaps personality. Although the evidence is scant, there is also some evidence to suggest that this "friend" will be more likely to delve into drug abuse again.
Unfortunately, these are the facts. I guess its my role to present them, and your (aviators/employers) role to act upon them. If your prepared to take the risk, and have adequate safeguards to manage that risk, then that is your executive decision.
I'm sorry if there is a need need to question my beliefs and values. Its not my intention to "blame the victim," and no, I am not in a position to take any sort of "moral highground," I'm just interested in helping manage the risk !