Oxytocin is a hypothalamic peptide hormone that is stored in the posterior pituitary gland. It is released into the bloodstream during parturition and lactation and is also involved in other social and sexual behaviors, neuropsyciatric disorders, and the maintenance of water and sodium homeostasis. Cayman's Oxytocin EIA Kit is a competitive assay that can be used for quantification of oxytocin in plasma. The EIA typically displays an IC50 (50% B/B0) of approximately 80 pg/ml and a detection limit (80% B/B0) of approximately 18 pg/ml.