The dose-dependent effects of testosterone on sexual function and on muscle mass and function.

Testosterone dose-response relationships are central to the issue of testosterone replacement therapy, within the context of both hypogonadal men and older men with declining testosterone levels. Dosages are also important when considering anabolic applications of testosterone for treating sarcopenia associated with chronic illness. The critical issue is whether increases in muscle mass and function can be achieved with dosages that will not adversely affect lipid profile, cardiovascular risk, and the prostate. The dose-response relationship and mechanisms of androgen action on the muscle for controlling it are being investigated.