Endogenous oxytocin is a hormone secreted by the supraoptic and paraventricular nuclei of the hypothalamus and stored in the posterior pituitary. It stimulates contraction of uterine smooth muscle during gestation and causes milk ejection after milk has been produced in the breast. Oxytocin has been associated with mating, parental, and social behaviors. Oxytocin is released during intercourse in both men and women, which has led to the belief that it is involved in sexual bonding. There is speculation that in addition to facilitating lactation and the birthing process, the hormone facilitates the emotional bond between mother and child.Oxytocin has also been studied in autism and have some sort of relation to the social and developmental impairments associated with the disease. Clinically, oxytocin is used most often to induce and strengthen labor and control postpartum bleeding. Intranasal preparations of oxytocin, used to stimulate postpartum milk ejection, are no longer manufactured in the U.S. Oxytocin was approved by the FDA in 1962.