Personally, I'm not all that concerned that people do things to destroy themselves. I see it all the time, with both drug users and non-drug users.
People should be encouraged to live intelligently and not do things that are harmful to themselves. But in the end, it is their decision.
As for high school kids - any kids who can afford steroids in high school and buy them without their parents knowledge are unproperly supervised.
College students SHOULD be smart enough to educate themselves regarding safe and unsafe steroid dosages.
You can ban steroids but covert performance enhancement will continue - especially when you consider the riches one can receive.
That's my point here - if baseball gets tough on steriods, then the incentive to use them goes way down. I am generally libertarian about recreational drugs - let people kill themselves as long as they are not harming others.