What hormone is responsible for stimulating milk production after birth?

Prolactin is the hormone responsible for stimulating milk production after birth. It is secreted by the anterior pituitary gland and plays a crucial role in lactation. Following childbirth, levels of prolactin rise in response to the dropping levels of estrogen and progesterone, which were high during pregnancy. Prolactin acts on the mammary glands to initiate and maintain milk synthesis, ensuring that the mother can provide adequate nourishment to her newborn.

In contrast, oxytocin, although related to breastfeeding, primarily facilitates the milk ejection reflex, promoting the let-down of milk rather than its production. Estrogen and progesterone, while important during pregnancy for the growth and development of breast tissues, do not stimulate milk production but rather prepare the breasts for lactation. Thus, the role of prolactin in initiating milk production is critical for successful breastfeeding post-delivery.