What protein is responsible for stimulating milk production?

Prolactin is the protein that plays a crucial role in stimulating milk production in the mammary glands. It is a hormone produced by the anterior pituitary gland, and its primary function is to promote lactation following childbirth. Prolactin levels increase during pregnancy and after delivery, which leads to the development of mammary glands and the production of milk necessary for nourishing infants.

In the context of lactation, prolactin acts by promoting the synthesis of milk proteins and fats, which are essential components of breast milk. The presence of prolactin leads to increased milk volume and is stimulated by the suckling of an infant, as this triggers the hypothalamus to signal the pituitary gland to release more prolactin.

While oxytocin also plays a role in the milk ejection reflex, or the "let-down" response, it does not stimulate milk production itself. Dopamine primarily functions as a neurotransmitter and is involved in inhibiting prolactin release. Follicle-stimulating hormone (FSH) is important in reproductive processes, particularly in regulating the development of reproductive cells in ovaries and testes, rather than in milk production.

Understanding the specific roles of these hormones helps clarify why prolactin is