Prolactin, Serum: is a hormone produced by the pituitary gland that helps regulate milk production in women and plays a role in reproductive and hormone balance in both men and women. Normal levels indicate healthy pituitary function and balanced hormone regulation. High prolactin can cause irregular periods, infertility, breast milk production in non-pregnant women, low libido, or sexual dysfunction in men.
Low prolactin is uncommon and usually not a concern.