the purpose of this study was to investigate the effects of oral contraceptives (ocs) on emotional reactivity and cognitive ability. previous research has suggested that oc users may experience blunted positive affect (pa) reactivity and that some women also experience negative mood side effects from ocs. in the present study, 149 participants (58 oc users, 46 nonusers, and 38 men) viewed three different emotional videos paired with music intended to evoke either happiness, sadness, or fear. after each emotional video, participants completed a facial emotions recognition task, and a gonogo task of inhibition. the hypothesis that women taking ocs would have lower pa reactivity compared to nonusers and men was not supported. however, a sex difference in negative emotional reactivity (women > men) was found and was strongest in oc users (oc users > men) and longer duration oc users. while a small sample size reduces validity of the findings, the hypothesis that oc users with current negative mood side effects would have faster response times than nonusers and men was not supported. however, a sex difference was evident in that men had slower response times to negative faces. also, men had slower response times than oc users, after sad and fear mood inductions. there was partial support for the third hypothesis that oc users would have more errors of commission than nonusers and men. oc users (and women as a group) made more errors of commission during the gonogo task compared to men, but only after the happy mood induction. also, oc users with current negative mood side effects had fewer errors of commission after the sad mood induction compared to oc users with no mood side effects. possible mechanisms are discussed for oc-associated impulsivity and for the possible reversal of such an effect in women experiencing oc mood side effects.