 Surprisingly, little or no sexual dysfunction, including loss of sex drive and decreased sexual activity, has been observed in clinical studies of monotherapy.The explanation for this is that do not lower androgen levels, and metabolites of testosterone like estrogens and neurosteroids may be of critical importance for maintenance of sex drive and function in males.In accordance, testosterone is locally aromatized into estradiol widely throughout the brain and estradiol appears to be the mediator of many of the central actions of testosterone.