Definition: Prolactin is a hormone made by the pituitary gland. Its main job is to make breast tissue grow in pregnancy and make milk after birth. MedlinePlus says levels are normally low in men and in women who are not pregnant or breastfeeding. A prolactin test measures it in a blood sample.
MedlinePlus says high prolactin can affect how the testicles work and cause a lower sex drive and erectile dysfunction in men. In women, it can cause period problems and infertility. So prolactin is one of the tests used to look for the cause of low sex drive, erectile dysfunction or infertility.
The most common cause of high prolactin, according to MedlinePlus, is a prolactinoma, a benign tumor of the pituitary gland. Certain medicines, an underactive thyroid and kidney disease can also raise it. The test cannot show the cause by itself.
The testosterone labels we checked (Depo-Testosterone and Xyosted) do not list prolactin as a routine lab. MedlinePlus lists it among the tests used to find the cause of low sex drive or erectile dysfunction in men.
Each lab sets its own reference range, so read your result against the range printed on your own report, and talk with your clinician about what it means for you.
Read more on Dose Track: Libido · Logging lab results in Dose Track