Bromocriptine, methyl testosterone and placebo for inhibition of physiological lactation: a controlled study.

Lactation occurs when the fully developed breast is released from the inhibitory influence which oestrogen and progesterone exert upon the action of prolactin. The use of oestrogens to suppress lactation depends on a continuation of the peripheral, that is, mammary, inhibition of prolactin. Androgens are also believed to act by inhibition of the action of prolactin on the mammary gland epithelium. Bromocriptine, when compared in a double-blind trial with orally administered methyl testosterone and placebo, gave almost complete relief of breast discomfort and congestion, though a small amount of milk production was seen. Methyl testosterone, in the dosage used in this study, was quite ineffective in suppressing lactation or breast symptoms.