just to get the terms straight, when they say tesstosterone, its an anabolic steroid, correct? >> it is an anabolic steroid but also a normal hormone. we all have normal amounts. >> the number of men that are taking it has tripled over the last ten years. what do you make of that? >> it's a huge money maker for the industry. you can't turn on tv for more than an hour. >> see all the ads. >> yes. that never used to be there. the advertising is very clever. are you fatigued or tired, not performing as well? >> it hits all the hot buttons, and everyone says, hey, that's me. >> that's me. >> it seems to me there's sort of three categories. it will help you, it will do nothing for you, it could potentially be harmful for you. when it comes to testosterone, if you're taking it, maybe not necessarily needing it, could it be harmful? >> yes, it can, of course. any drug can be harmful, but relatively speaking, compared to other anabolic agents, not so. >> human growth hormone? >> same thing. >> there's this notion hour hormone levels drop, certain hormones, as we age. with women, they t