The release of prolactin by medroxy-progesterone acetate in human subjects.

Medroxyprogesterone acetate an injectable contraceptive when administered to four lactating women at a dose of 150 mg every three months significantly raised prolactin levels over those observed in four control women. Prolactin levels were higher at all times during 4-17 weeks in the drug-treated women, irrespective of whether the samples were collected before or after suckling. It was also observed that while suckling clearly released prolactin in both groups the difference was greater in the women receiving the injection, indicating that the drug enhanced the release of prolactin in response to the suckling stimulus.