Many factors determine life span, of course, but it is a fact that men who have been castrated live about as long as women do. In what way exactly testosterone might shorten male lives is not known. Testosterone levels in men fall by about 1 percent a year beginning in their forties, prompting many to take supplements in the hope of boosting their sex drive and energy levels. The evidence that it improves sexual performance or general virility is thin at best; there is much greater evidence that it can lead to an increased risk of heart attack or stroke.
