Prolactin is a hormone that the pituitary gland produces. High levels of prolactin may occur due to medications, health conditions, or prolactinomas, which are benign tumors of the pituitary gland.

Prolactin plays an important role in the healthy functioning of the body. Insufficient or excessive levels of prolactin may cause health issues.

Noncancerous tumors of the pituitary gland, called prolactinomas, can cause high levels of prolactin and other health conditions.

In this article, we look at the role of prolactin in the body, symptoms of prolactinomas or high prolactin levels, and treatments for insufficient or excessive levels of this hormone.

A note about sex and gender

Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.

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Prolactin is a hormone that helps breast development, particularly in females. It helps the body maintain an overall stable condition and also allows nursing individuals to lactate.

The pituitary gland produces prolactin. This gland sits at the base of the brain and helps regulate hormones in the body.

Insufficient or excess prolactin levels can cause health issues.

A prolactinoma is a noncancerous tumor in the pituitary gland. Prolactinomas produce prolactin, which can lead to high levels of this hormone in the body.

There is no known cause for prolactinomas, but genetics may play a part in some cases. For example, multiple endocrine neoplasia type 1 is a genetic disorder that may increase the risk of developing prolactinomas.

Prolactinomas are more common in females than males and are more prevalent in females aged 25–34 years.

It is typical for prolactin levels to rise during pregnancy and chest or breastfeeding.

Other factors can also cause a slight, temporary spike in prolactin levels, including:

  • physical stress on the body
  • exercise
  • sexual intercourse
  • eating a meal
  • nipple stimulation
  • chest injury
  • epileptic seizures

Aside from prolactinomas, high prolactin levels may also result from health conditions or taking certain medications.

Medications

Dopamine, a chemical in the brain, helps control prolactin production. Medications that affect dopamine levels may cause increased prolactin levels.

Medications that may cause high prolactin levels include:

Health conditions

Certain health conditions may cause a rise in prolactin levels, such as:

Prolactinomas or high prolactin levels in females may cause:

High prolactin levels in males may cause erectile dysfunction or low testosterone levels, which may cause a loss of interest in sex.

Males may also experience headaches and milk-like discharge from the nipple.

High prolactin levels may have links to certain mood disorders. A 2021 study found that people with major depressive disorder (MDD) had higher prolactin than those without the condition.

Prolactin helps regulate stress and also has associations with anxiety, weight gain, and hostility. Higher levels of the hormone may also increase the risk of developing psychosis.

MDD affects how the nervous system and endocrine system interact. The above 2021 study also suggests that MDD may also disrupt the production of prolactin.

To diagnose high prolactin levels, doctors will take a blood test to measure the amount of prolactin in the blood.

If people have high prolactin levels, doctors will then carry out imaging tests to check for a prolactinoma.

Doctors may use an MRI scan to create a detailed image of the pituitary gland and surrounding area. If an MRI is unsuitable, a person may undergo a CT scan.

Imaging tests allow doctors to see if a prolactinoma is present and identify its location and size.

Treatment can help to return prolactin levels to typical levels and treat any prolactinomas that may be present.

Medication

The most common treatment for prolactinomas is medication, which can shrink the prolactinoma and regulate prolactin levels.

Dopamine agonists are medications that act similarly to dopamine in the brain. They are an effective treatment in shrinking prolactinomas and controlling prolactin levels.

Doctors may prescribe bromocriptine, which people may need to take 2–3 times daily. They may also need cabergoline, which may be more effective and have fewer side effects than bromocriptine. People may need to take this 1–2 times a week.

A person may need to take medication for 2 years or more until the prolactinoma is no longer visible. If prolactin levels rise, they may have to continue medication to reduce them again.

If medications are causing high prolactin levels, stopping taking the drug will usually cause prolactin levels to return to typical levels within 3–4 days.

However, it is important to speak with a doctor before stopping any prescription medication.

Surgery

If medication is ineffective in treating a prolactinoma, people may require surgery to remove the tumor. A doctor will perform the surgeries under a general anesthetic.

Types of surgery to remove a prolactinoma include:

  • Transsphenoidal surgery: This is the most common type of prolactinoma surgery. A surgeon will make a cut behind the nasal cavity or under the upper lip to carry out the procedure.
  • Transcranial surgery: People may require this type of surgery if the prolactinoma is large or has spread outside the pituitary gland. A surgeon will make an opening in the skull to remove the tumor.

The pituitary gland produces the hormone prolactin, which is important for the proper functioning of the body.

However, high prolactin levels can cause health problems, such as irregular periods and infertility in females and low testosterone levels and erectile dysfunction in males.

Prolactinoma, a benign tumor of the pituitary gland, can also cause high prolactin levels. People may need medications or surgery to shrink the tumor and reduce prolactin levels.

If medication or an underlying health condition is causing high prolactin levels, stopping the medication or treating the underlying condition may help return prolactin levels to expected levels.

If people have any symptoms of high prolactin levels or prolactinoma, they will need to speak with a doctor for a diagnosis.