Gynecomastia caused by estrogen containing hair lotion.

Two men at the age of 48 and 54 yr developed gynecomastia and lost their potency after the use of estrogen containing hair lotions. During exposure to the lotion the levels of 17-beta estradiol were increased, whereas the levels of testosterone and gonadotropins were depressed. Thus, a previous application of such hair lotions should be considered in the differential diagnosis of gynecomastia.