Prolactin Most Popular

The Prolactin test contains 1 test with 1 biomarker.

Description: A prolactin test is a blood test that measures the Prolactin levels in your blood's serum, and it is useful in identifying unexplained problems with breastfeeding, menstrual cycles, and infertility.

Also Known As: PRL Test, Prolactin Blood test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: No preparation required

When is a Prolactin test ordered?

Prolactin testing may be requested in the following situations:

  • If someone is experiencing prolactinoma symptoms such as inexplicable headaches, breast nipple discharge, and or vision impairment.
  • Infertility or irregular menstrual periods in a woman.
  • A male that has low testosterone or has signs such as diminished sex drive, nipple discharge, or infertility.

When a person has a prolactinoma, prolactin levels may be requested on a regular basis to track the tumor's progress and response to treatment. They may also be ordered at regular intervals to check for the return of prolactinoma.

When a doctor suspects a person has a pituitary condition such hypopituitarism, prolactin levels, as well as other hormone levels like growth hormone, may be requested.

Prolactin concentrations are sometimes measured when a person has an illness or is receiving medication that may impair dopamine production.

What does a Prolactin blood test check for?

The anterior region of the pituitary gland, a grape-sized structure located at the base of the brain, produces prolactin. Prolactin is a hormone that promotes lactation and is found in low concentrations in men and non-pregnant women. This test determines how much prolactin is present in the blood.

Dopamine, a brain neurotransmitter, regulates and inhibits prolactin release. Prolactin levels are typically high throughout pregnancy and shortly after childbirth. The hormones prolactin, estrogen, and progesterone enhance the production of breast milk during pregnancy. Prolactin aids in the initiation and maintenance of breast milk supply after childbirth. If a woman does not breastfeed, her prolactin level quickly returns to pre-pregnancy levels if she does not nurse. Suckling by the infant has a vital function in the release of prolactin if she does nurse. The amount of prolactin emitted by the pituitary, as well as the amount of milk produced, have a feedback system.

A prolactinoma, a pituitary gland tumor that generates excessive prolactin production, is a common cause of an unusually raised prolactin level. The most frequent type of pituitary tumor is prolactinoma, which is usually benign. They are more common in women, but they can also be found in men. The size and location of the tumor, as well as the unintended effects of excess prolactin, such as milk production in a woman who is not pregnant or nursing and, occasionally, in a man, can cause problems.

When the anterior pituitary gland and/or tumor grow large enough, they can put pressure on the optic nerve, causing headaches and visual abnormalities, as well as interfering with the pituitary gland's other hormones. Prolactinomas in women can induce infertility and menstrual abnormalities, while in men, they might cause a gradual loss of sexual function and libido. Prolactinomas can cause damage to the surrounding tissues if they are not treated.

Lab tests often ordered with a Prolactin test:

  • FSH
  • LH
  • Testosterone
  • DHEA-S
  • Estrogen
  • Estradiol
  • Estrone
  • Estriol
  • Progesterone
  • Androstenedione

Conditions where a Prolactin test is recommended:

  • Pituitary Disorders
  • Infertility
  • Pregnancy
  • PCOS
  • Thyroid Diseases

Commonly Asked Questions:

How does my health care provider use a Prolactin test?

Prolactin levels can be used for a variety of purposes. Prolactin is a hormone generated by the pituitary gland, and its major function is to assist pregnant and nursing women in initiating and maintaining breast milk production.

Prolactin testing, in combination with other hormone tests, may be used to:

  • Determine what is causing the production of breast milk that isn't related to pregnancy or breastfeeding
  • Find out what's causing men's infertility and erectile problems.
  • Determine the reason of a woman's menstrual irregularity and/or infertility.
  • Detect and diagnose prolactinomas, track their therapy, and look for recurrences.
  • Examine anterior pituitary function or any other pituitary problems.

What do my prolactin test results mean?

Prolactin levels in the blood of men and nonpregnant women are usually very low. Prolactin levels must be analyzed according to the time of day they are taken. Over the course of a 24-hour period, the levels will rise during sleep and peak in the morning. A person's blood should be drawn 3 to 4 hours after they wake up.

During pregnancy and while the mother is nursing, a high amount of prolactin is typical.

High prolactin levels can also be noticed in the following:

  • Prolactin-producing and -releasing tumors
  • Eating disorders such as  anorexia nervosa
  • Hypothalamic diseases
  • Hypothyroidism
  • Kidney disease
  • Liver disease
  • Polycystic ovarian syndrome
  • Other tumors and disorders of the pituitary gland

Low levels of prolactin are not normally treated, but they could indicate a general decline in pituitary hormones caused by a pituitary condition such hypopituitarism.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.

The following is a list of what is included in the item above. Click the test(s) below to view what biomarkers are measured along with an explanation of what the biomarker is measuring.

Also known as: PRL


Prolactin is a hormone produced by the anterior portion of the pituitary gland, a grape-sized organ found at the base of the brain. Prolactin secretion is regulated and inhibited by the brain chemical dopamine. Normally present in low amounts in men and non-pregnant women, prolactin's primary role is to promote lactation (breast milk production). Prolactin levels are usually high throughout pregnancy and just after childbirth. During pregnancy, the hormones prolactin, estrogen, and progesterone stimulate breast milk development. Following childbirth, prolactin helps initiate and maintain the breast milk supply. If a woman does not breastfeed, her prolactin level soon drops back to pre-pregnancy levels. If she does nurse, suckling by the infant plays an important role in the release of prolactin. There is a feedback mechanism between how often the baby nurses and the amount of prolactin secreted by the pituitary as well as the amount of milk produced. Another common cause of elevated prolactin levels is a prolactinoma, a prolactin-producing tumor of the pituitary gland. Prolactinomas are the most common type of pituitary tumor and are usually benign. They develop more frequently in women but are also found in men. Problems resulting from them can arise both from the unintended effects of excess prolactin, such as milk production in the non-pregnant woman (and rarely, man) and from the size and location of the tumor. If the anterior pituitary gland and/or the tumor enlarge significantly, it can put pressure on the optic nerve, causing headaches and visual disturbances, and it can interfere with the other hormones that the pituitary gland produces. In women, prolactinomas can cause infertility and irregularities in menstruation; in men, these tumors can cause a gradual loss in sexual function and libido. If left untreated, prolactinomas may eventually damage the tissues around them.
*Process times are an estimate and are not guaranteed. The lab may need additional time due to weather, holidays, confirmation/repeat testing, or equipment maintenance.

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