This is a terrible idea. First, it would not solve the problem. If you allow athletes to take a little of something, then you would have athletes finding ways to cheat by taking a lot of something — to give them an advantage. Because it's all about gaining an unfair advantage over the rest of the field. Just allowing steroids is not going to fulfill that goal.
Second, it's a terrible idea to condone these substances which can have severe consequences for the longterm health of the athletes. Perhaps what is needed is a long, hard look at the highschool athletics systems that are putting young athletes under such pressure that they are willing to risk their health for a fleeting moment of teenage glory.
Which is one of the reasons that allowing Olympic athletes to take steroids is such a bad idea. Many of them are teenagers, or at least were teenagers when they started. These substances can have huge detrimental effects on their growth and development, particularly in sexual development — for both males and females.