Prolactin is produced by the pituitary gland in the brain. Prolactin is mainly used to help women produce milk after childbirth. It's also important for both male and female reproductive health. A prolactin test may be ordered to check for the cause of:

  • Breast milk production that is not related to childbirth (galactorrhea)
  • Decreased sex drive (libido) in men and women
  • Erection problems in men
  • Infertility
  • Irregular or no menstrual periods (amenorrhea)

During pregnancy, prolactin levels may increase. After the baby is born, prolactin levels may stay high if you are breastfeeding. In women who do not breastfeed, prolactin levels generally return to normal soon after giving birth. After breastfeeding for several months, prolactin levels may also return to normal levels even if breastfeeding continues.

Normal value ranges of prolactin may vary among different laboratories. Some labs use different measurements or perform the test differently. Talk to your doctor about the meaning of your specific test results.