Androgen replacement in men with hypogonadism and erectile dysfunction.

The prevalence of hypogonadism and erectile dysfunction (ED) increases with age. Hypogonadism also is frequently associated with decreased libido and ED. Testosterone replacement therapy for hypogonadal ED is effective in restoring sexual desire and erectile function, especially in younger and healthy men. It appears to be less effective in older men with comorbid diseases that may cause ED. Therapy should be individualized, considered carefully, and closely monitored because of potential risks, especially in older men. The FDA has approved several testosterone delivery systems. These include a buccal testosterone tablet, intra-muscular injections, transdermal and subcutaneous forms. There also are several promising experimental androgens under investigation including non-steroidal selective androgen receptor modulators (SARMs).