Background: Oral Contraceptives (OCs) containing estrogen and progesterone analogues are widely used, but their cognitive impact remains controversial. Given established evidence for neuroactivity of reproductive hormones, there is clear investigative rationale. Existing literature is inconclusive, with evidence that OCs improve verbal memory, and that greater androgenic activity may improve visuospatial ability, a male-favouring domain. We aimed to examine the impact of OCs in other sexually dimorphic cognitive domains.

Methods: 35 volunteer OC-users underwent cognitive evaluation with CogState software at two points in the menstrual cycle, coinciding with placebo ‘sugar’ pill and hormone-containing ‘active’ pill phase. Repeated measures ANOVAs were performed assessing effects of pill phase (sugar/active) and progestin androgenicity on performance.

Results: Analysis by pill phase revealed significant improvement in verbal memory during active pill use. Analysis by progestin class showed superior performance by users of androgenic progestins in both visual memory and facial affect discrimination. An interaction between pill phase and progestin class was seen in verbal learning, with improvement in anti-androgenic progestin users during the active phase but decline in androgenic progestin users.

Conclusion: Our results support findings that OCs may improve verbal memory, and extend the impact of OC androgenicity across multiple sexually-dimorphic cognitive domains. In this study, androgenic OCs enhanced visual memory and facial affect discrimination (male-favouring tasks) but impaired verbal learning (female-favouring tasks), with opposite effects seen in users of anti-androgenic OCs. Establishing cognitive effects of OCs allows better-informed contraceptive choices.