oxytocin

A short polypeptide hormone, C₄₃H₆₆N₁₂O₁₂S₂, released from the posterior lobe of the pituitary gland, that stimulates the contraction of smooth muscle of the uterus during labor and facilitates ejection of milk from the breast during nursing.

A hormone that stimulates contractions during labour/labor, and then the production of milk.

hormone secreted by the posterior pituitary gland (trade name Pitocin); stimulates contractions of the uterus and ejection of milk