Prolactin / macroprolactin

Prolactin is a peptide hormone secreted by the pituitary gland. In women, it is important and necessary for the development of the mammary glands and regulates milk production. Factors such as breastfeeding, sexual activity, sleep, dehydration, and stress directly stimulate prolactin synthesis in the pituitary.

Prolactin testing is important when evaluating possible infertility, menstrual cycle disorders, and should also be performed if milk production begins when it is not related to childbirth. In men, the test is important in cases of erectile dysfunction. Elevated prolactin levels may indicate a pituitary tumor (prolactinoma). Increased levels can also be caused by metastatic breast cancer. In women, high prolactin levels may lead to breast discharge, enlargement, or increased sensitivity. In men, elevated prolactin suppresses testosterone synthesis, causing erectile dysfunction and impotence.

Decreased prolactin levels may occur in cases of destructive pituitary diseases, and levels may also decrease if milk production does not occur after childbirth.