inhibitory control is a major aspect of executive functioning, and ovarian hormones (e.g., progesterone and estrogen) have been found to affect processes related to inhibitory control. this was the first study to examine the effects of sex, menstrual cycle phase (follicular, luteal), and oral contraceptives (oc) (users, nonusers) on four different types of inhibition (response inhibition, deferred gratification, reversal learning, and emotional reactivity) across two studies. the first study examined self-reported inhibitory control in 372 participants at two time points two-weeks apart. the second study (n = 162) compared groups on several laboratory tasks of inhibitory control that were given after three mood primes (sad, happy, fear). group differences (sex, cycle phase, oc use) were examined. women showed: (a) higher negative emotional reactivity than men across self-report and laboratory measures, including relatively higher accuracy with negative than positive self-associations when sad; (b) more errors of commission than men on a gonogo task after sad and fear mood induction; and (c) more problems with self-reported perseverative thinking than men. no sex differences were found for self-report measures of response inhibition; or any measures of deferred gratification. regarding cycle phase effects, follicular phase women had more errors of commission than luteal phase women after fear mood induction, and this follicular phase effect explained the sex difference. cycle effects were not found for reversal learning, emotional reactivity, or self-report measures of response inhibition. also, no cycle effects were found for deferred gratification. there was no evidence that oc users and non-users differed on any of the four types of inhibitory control either on self-report or lab measures, suggesting no effects of ocs. findings are discussed in terms of understanding the role of endogenous and exogenous hormones in inhibitory control.