Menstrual cycle phase predicts women's hormonal responses to sexual stimuli.

A robust body of research has demonstrated shifts in women's sexual desire and arousal across the menstrual cycle, with heightened desire and arousal coincident with heightened probability of conception (POC), and it is likely that ovarian hormones modulate these shifts. However, studies in which women are exposed to audiovisual sexual stimuli (AVSS) at high POC (mid-follicular) and low POC (luteal) phases have failed to detect significant differences in genital or subjective arousal patterns based on menstrual cycle phase. Here, we tested whether hormonal responsivity to AVSS differs as a function of cycle phase at testing, and whether phase during which participants were first exposed to AVSS influences hormonal responsivity in subsequent test sessions. Twenty-two naturally cycling heterosexual women were exposed to AVSS during the follicular and luteal phases, with phase at first test session counterbalanced across participants. Salivary samples were collected before and after AVSS exposure. Estradiol increased significantly during both follicular and luteal phase sessions, and increases were higher during the follicular phase. Testosterone (T) increased significantly only during the follicular phase session, while progesterone (P) did not change significantly during either cycle phase. Session order and current cycle phase interacted to predict P and T responses, such that P and T increased during the follicular phase in women who were first tested during the luteal phase. These data suggest that menstrual cycle phase influences hormonal responsivity to AVSS, and contribute to a growing body of clinical and empirical literature on the neuroendocrine modulators of women's sexuality.