Roger Clemens on trial for lying to Congress

Baseball legend Roger Clemens is on trial for lying to Congress about his use of steroids. According to Wikipedia, steroids were added to the list of Schedule III drugs in 1990. I know, I know, Wikipedia is not reliable. I assume it's probably reliable enough for generic information like this. Anyway, on to steroids, Congress and Roger Clemens. First, why are steroids illegal? I don't see any power enumerated in the Constitution granting the federal government the authority to ban a substance like steroids. But let's save that for another day. Second, if you still believe Wikipedia, steroids don't have the addictive qualities that would make it a candidate for listing as a Schedule III drug according to the DEA and FDA. But I guess Congress couldn't let big public scandal such as Ben Johnson being disqualified from the Olympics after winning a gold medal go to waste. They just had to do something and that usually causes a loss of money or rights, or both, for Americans. But even that's now what this post is about. This article is about Roger Clemens perjuring himself before Congress. He allegedly lied to them. If lying before Congress is a crime, then I'd like to see most of Congress put on trial for perjury. I bet there are very few of them that haven't lied while speaking on the House or Senate floor. I don't see how they can bring charges on someone else lying to them when they regularly lie to each other and to the American people. Or maybe they just think they are above the rules.