I've said it before, I'll say it again, and I'll keep saying it until this situation is reasonably adjudicated.
As long as the player is taking a LEGAL substance, obtaining that substance LEGALLY, and using it under the supervision of a LEGAL MEDICAL PROFESSIONAL, it should not be the business of ANY sports league to determine what course of treatment a person takes.
if a player chooses to take a PED that has potential bad future consequences, that should be totally and completely up to him (or her). If they are under the supervision of a legal medical professional, then the risks involved have to be explained to the player, as that is a requirement a doctor has in order to keep his license.
If it's LEGAL to use, it should be their choice.
If the player is getting some supplement illegally, is getting a supplement that has been deemed illegal to use, or uses something while not under the supervision of a legally licensed medical professional, then he is cheating and should face the consequences.
Baseball (and every other sport as far as I can tell) already allows some substances/drugs/supplements that are borderline, and some that are legally defined as steroids (cortisone, for example, has been in use for decades now, and some players get injected with that stuff several times a year to stay on the field).
Most of these so-called "PEDs" are not really "performance enhancing", they are more like "performance enabling" ergo, they do not necessarily aid in getting a player to perform BETTER, but assist in recovery to the point where they allow them to recover from injury and actually PLAY instead of sitting on the DL. (Mark McGwire, perfect example).
Isn't that what we should be HOPING for? Talented players to actually be able to play the game they are the best in the world at? It seems counter-intuitive to me that leagues forbid treatments that could aid in health recovery and keep the greatest players on the field. All this does is drive the topic underground, and force players to go to shady lengths to obtain this stuff. Make it above board. Make it legal (again as long as it's legal to use, legally obtained, and legally monitored).