A growing body of medical evidence substantiates the popular notion th
at androgens regulate several aspects of behavior in men; in addition,
recent studies suggest that androgens modulate certain behaviors in w
omen as well. In hypogonadal men, androgen replacement leads to improv
ed libido and other behaviors, but erectile responses to erotic stimul
i do not seem to be affected. Similarly, in normal men, suppression of
endogenous androgens to very low levels leads to decreases in a varie
ty of sexual behaviors. Sexual function, however, may be maintained wi
th lower androgen levels than are required for other target tissues. A
lthough higher androgen levels lead to increased aggressive behaviors
in animals, this relationship is probably not in men. In women, correl
ations between levels of circulating androgens and sexual behaviors ar
e variable. In some naturally menopausal women with decreased libido,
androgen replacement may be effective when estrogen replacement has fa
iled, but few studies have examined this question. In contrast, severa
l studies suggest that in some surgically menopausal women, replacemen
t of estrogen and androgens may lead to better psychological and sexua
l functioning than replacement of estrogen alone. However, more data a
re needed before this approach can be recommended to every surgically
menopausal woman.