Since these persons are noncompetitors, no one can cheat them by using steroids. The only reasons most of them do not use steroids is that they are afraid they may be jailed and they are afraid of the dire physical consequences the government and medical propagandists promise will batter their bodies. Many of these ads brag that their legal drugs are better than steroids. Persons who use legal exotic supplements are falling into the trap of thinking that legality magically confers legitimacy and illegality takes it away. But if something is wrong only because it is against the law then it is a very trivial wrong.
Lawyers use fancy language to mark the difference.
Some substances are banned by some sports federations despite the fact that they are not drugs. You can buy androstenedione in supermarkets. I think that, since he breaks no law but only an arbitrary federation regulation, he may do as he wishes. Consider how arbitrary it is to ban adrostenedione but not creatine, which may actually be more effective. No athlete should brag that he follows the requirement not to use andro while he is loading up on creatine.