Endocrine properties and mechanism of action of oral contraceptives.

TLDR: The clinical effect of oral contraceptive seems to be to inhibit the release of "releasing factors" from the hypothalamus, which keeps production of follicle stimulating hormone and luteinizing hormone to a minimum which in turn prevents ovulation.

Abstract: The biological properties that may account for the effectiveness of oral contraceptives are progestational activity estogenicity and hormonal activity. The primary effect of most oral contraceptives is the inhibition of ovulation. The clinical effect of oral contraceptive seems to be to inhibit the release of "releasing factors" from the hypothalamus. This keeps production of follicle stimulating hormone (FSH) and luteinizing hormone (LH) to a minimum which in turn prevents ovulation. The presence of the exogenous hormones maintains the uterus and other target organs and thus simulates a cycle.