Oxytocin
Oxytocin (Oxt) is a peptide hormone and neuropeptide. Oxytocin is normally produced by the paraventricular nucleus of the hypothalamus and released by the posterior pituitary. It plays a role in social bonding, sexual reproduction, childbirth, and the period after childbirth. Oxytocin is released into the bloodstream as a hormone in response to stretching of the cervix and uterus during labor and with stimulation of the nipples from breastfeeding. This helps with birth, bonding with the baby, and milk production. Oxytocin was discovered by Henry Dale in 1906. Its molecular structure was determined in 1952. Oxytocin is also used as a medication to facilitate childbirth.
Pillow talk
The content of pillow talk typically includes the sexual act itself, stories and confessions, expressions of affection and appreciation, and playful humor. A line of research done on pillow talk has revolved around the hormone known as oxytocin; this "bonding hormone" is related to other effects, such as decreasing stress, decreasing perceptions of social threat, increasing bonding, and increasing the ability to read emotional cues. This hormone has been known to increase in the body proceeding sexual activity between two people that have reached the point of orgasm. The individuals involved in this act of coitus can benefit from this process by opening up in a sense of communication and trust. A study done by Amanda Denes (2012), shows that partners who orgasm are more likely to engage in the act of pillow talk versus partners who do not orgasm.