Charting Salivary Oxytocin Across an Episode of Naturally Occurring Partnered Sex

Oxytocin (OXT) has been linked to sexual behavior across several studies. However, scant work exists that investigates OXT concentrations across a sexual encounter and researchers have yet to examine OXT concentrations during partnered sexual activity in the home environment. In the present study, a non-clinical sample of 49 mixed-sex (i.e., 49 women, 49 men) young adult romantic partners were invited to engage in sexual activity within their home environments. Participants collected their own saliva samples before and after sex, which were then assayed for OXT. Dyadic analyses identified unique OXT trajectories for women and men and helped clarify mixed findings in prior work. Although time was not a significant predictor, the pattern of means indicated that women's OXT concentrations were highest at the start and end of the sexual episode, whereas men's OXT concentrations increased from the start to the end of the sexual episode. The findings also identified synchronous changes between women and men's OXT, but only within the post-sex time interval (immediately post-sex, 20 min post-sex, and 40 min post-sex). Additionally, OXT concentrations pre- and post-sex were not associated with orgasm in ways that prior work would suggest. Implications for work on OXT, biological synchrony, and methodological comparison are discussed.