Prolactin (Serum) – High-Performance Liquid Chromatography (HPLC) Measurement

Why This Test Might Be Ordered

Your doctor may recommend this test if you have symptoms like unexplained breast milk production in men, infertility, irregular menstrual periods, headaches, or signs of a pituitary tumor. It may also be checked during pregnancy, before certain medications, or if you have conditions like hyperprolactinemia or hypoprolactinemia.

Your doctor will explain how to prepare. Typically, you may need to avoid certain medications (like some antidepressants or antipsychotics) for a few days before testing, as they can affect prolactin levels. Avoid smoking and caffeine before the blood draw, as they may also influence results.

A healthcare professional will draw blood from a vein in your arm. You may feel a slight pinch, but it usually doesn’t cause significant discomfort. The blood sample will be sent to a lab for analysis using high-performance liquid chromatography (HPLC) to measure prolactin concentration.

Results are interpreted by your doctor based on your symptoms, medical history, and other tests. Elevated prolactin levels may suggest conditions like pituitary tumors or certain medications, while very low levels might indicate rare hormonal deficiencies.

High prolactin levels can be caused by tumors in the pituitary gland, certain medications (like antipsychotics or birth control), kidney disease, or thyroid disorders. Low prolactin levels are less common but may result from pituitary damage or genetic conditions.

Abnormal prolactin levels can impact fertility, hormone balance, and other bodily functions. High levels may interfere with ovulation in women and sperm production in men, while low levels can affect milk production and reproductive health. Early diagnosis helps manage symptoms and prevent complications.

If your prolactin levels are abnormal, your doctor may order follow-up tests to monitor changes over time. They may also adjust medications or recommend treatments like dopamine agonists to lower prolactin levels, depending on the underlying cause.