I regularly ride with an MD and recently talked to him about all of these ads on TV. I wasn't thinking about taking the drugs because I'm of the persuasion that taking as few drugs as possible is the best choice. I firmly believe that the more a drug is advertised the less value it likely has except for the profit margin of the so-called ethical drug companies. I have a similar view of nutritional supplements. In any case he said that for a normal man taking testosterone supplements will suppress your own production, possibly shrink the size of your testes, and if you happen to have prostate cancer (common in older men) it can increase the rate at which it grows. That is certainly true as one of the treatments for prostate cancer is suppressing testosterone production. It is expensive, hence they can afford to bombard us with endless ads. The last thing he said was that once the drug companies get you on it, it may be for life as the suppression it causes may not be reversible.