Contraceptive pills generally contain the hormones estrogen and progesterone. If taken daily from the 4th day after menses the abnormal elevation of these hormones acts upon the hypophysishypothalamus endocrine axis inhibiting the FSH and LH secretions. Since these hormones then do not reach their normal high levels during the menstrual cycle ovulation does not occur.
(Treatment with contraceptive pills must be initiated under medical supervision.)
