Which hormone is responsible for moving milk through the mammary ducts?

Oxytocin is the hormone that plays a crucial role in moving milk through the mammary ducts during breastfeeding. It is released in response to the baby’s suckling and stimulates the contraction of myoepithelial cells surrounding the alveoli in the breast, which facilitates the ejection of milk from the glands into the ducts, making it available for the infant to consume.

Prolactin, while vital for milk production, does not directly aid in the transport of milk; its main function is to stimulate the mammary glands to produce milk. Progesterone and estrogen have roles related to breast development and preparing the breast tissue for lactation but do not have a direct role in moving the milk itself during breastfeeding. Hence, oxytocin is specifically responsible for the physical movement of milk through the mammary ducts.