Which hormone stimulates the alveolar cells of the breast to promote milk production following birth?

Prolactin is the hormone that is primarily responsible for stimulating the alveolar cells in the breast to promote milk production following birth. After delivery, the levels of estrogen and progesterone drop significantly, which removes their inhibitory effect on lactation. Prolactin, which is produced by the anterior pituitary gland, increases in response to the infant's sucking at the breast, leading to the synthesis of milk in the mammary glands. This essential role of prolactin helps ensure that the mother can provide nourishment for her newborn through breastfeeding.