Which of the following is NOT a described function of prolactin?

• A. Prepares breasts for breastfeeding during pregnancy and after birth
• B. Promotes synthesis of milk
• C. Mood-elevating and calming effects on mother
• D. Inhibits milk production

Answer: (D)

Prolactin’s main role is to support lactation. It stimulates milk synthesis in the mammary glands and helps prepare the breasts for breastfeeding during pregnancy, with gland development and secretory capability increasing to enable milk production after birth. It’s also associated with maternal behaviors and can have mood-modulating effects, which can feel calming or uplifting for some mothers. The idea that prolactin inhibits milk production goes against its primary action—prolactin drives milk production, while inhibition would come from other regulators such as dopamine. Therefore, the statement that prolactin inhibits milk production is not a described function.