It seems like you can't listen to any radio station, without hearing commercials for some drug that helps men with low testosterone. They tell you all the side effects of low testosterone like, Lack of Energy, Mood Problems including Depression, Increase of Body Fat, Loss of Muscle Mass and Strength, Sexual Disfunction, Decreased Libido or Sex Drive, and Erectile Dysfunction. But none of them seem to ask, why do all these men have low testosterone now? What has changed, that has made males testosterone levels decrease? The answer lies in many areas. Including Diet, Exercise and Environment. To try and figure out how or why so many males testosterone levels are dropping, you must first look at how the body produces testosterone.