Testosterone occurs naturally in the body. Some other substances work via increasing red blood cell count etc, if this stuff was so "bad" for you then it would not be used medicianlly.
Did you know that taking acid or smoking pot will make you stare at the sun until you go blind? Thats according to what the government once told people. You are fed misinformation to keep you away from these items, for what stupid reason I really dont know. Congress makes these laws, how old are those guys and what do they really know about steroids? Not a damn fuckin thing.
Yet alcohol or smoking cigarettes is still quite legal, even though we know how bad it is for us. Drunk driving, drinking yourself to death, smoking yourself to death, beating your wife in a drunken rage, all obtainable at your local liquor store.