Medical management has been shown to produce variable results. Reports of successful medical treatment have been most consistently linked to instances when the gynecomastia is of recent onset and is caused by testosterone deficiency. (However, many reports of “successful” medical treatment of gynecomastia are simply misconstrued attempts to treat adolescent individuals with normal findings during puberty that would have resolved spontaneously. It must be stressed that minimal development of the breast bud during puberty is a normal finding in males that resolves in time with no treatment.)
Testosterone administration has inconsistent effects in persons with Klinefelter syndrome, but it can cause a dramatic improvement in those with other forms of testicular failure (eg, anorchia, viral orchitis). Testosterone therapy involves an element of uncertainty because testosterone can serve as a substrate for extraglandular estrogen formation. Under some circumstances (eg, a patient with liver disease), androgen therapy can cause a disproportionate increase in plasma estrogen levels.
Various drug regimens have been tried for the treatment of gynecomastia. These drugs include the antiestrogens tamoxifen  and clomiphene, the aromatase inhibitor testolactone, and danazol (a weak androgen that inhibits gonadotropin secretion and causes a decrease in plasma testosterone).