Prolactin: What is it? Function, Tests, Procedure, Risks, Results, Elevated Levels, Treatments and Complications

It is a hormone that affects many different hormones in the body.

Present in both men and women, it rarely causes problems, but those who are serious about their health need to understand what it is, how it affects the overall health and well-being of the body.

Prolactin, as its name implies, is a hormone that promotes lactation (production of breast milk) in mammals and is responsible for a number of other functions and systems.

Prolactin is created in the front part of the pituitary gland in the brain, as well as in the uterus, brain , breasts, prostate, fat tissue, skin, and immune cells.


Prolactin is released when a newborn baby suckles on its mother’s breast, causing milk production. However, this is only the main and best known purpose of prolactin.

The function of prolactin is still being studied, but research appears to show a variety of purposes for this hormone.

For example, it also regulates behavior, the immune system, metabolism, reproductive systems, and many different bodily fluids. This makes it a crucial hormone for overall health and well-being for both men and women.

Prolactin Tests and Why They Are Needed


Women with symptoms of prolactinoma (benign tumor of the pituitary gland) may need the test as this tumor causes high prolactin levels.

Symptoms of prolactinoma in women include:

  • Headaches for no reason.
  • Visual disability.
  • Galactorrhea or lactation outside of childbirth or lactation.
  • Pain or discomfort during sex.
  • Abnormal growth of body and facial hair.
  • Abnormal acne.

The test is usually done in people with prolactinoma to monitor the response of the tumor to treatment.

Also, the prolactin test may be necessary if you have fertility problems or irregular periods. The test can also rule out other problems with the pituitary gland or hypothalamus.


Men may need the test if they show symptoms of prolactinoma.

Symptoms of prolactinoma in men include:

  • Visual disability.
  • Unexplained headaches
  • Abnormal lack of body and facial hair.
  • Erectile dysfunction.
  • Reduction of sexual desire.
  • Fertility problems

How is the test performed?

A prolactin test is like a blood test. Takes a few minutes in the office or lab. You don’t need to prepare for that.

The sample is usually taken three to four hours after waking up in the morning. A blood sample is drawn from a vein located in the arm. There is very little pain.You may feel only a slight pinch when the needle goes in and some mild pain afterward.

Some birth control pills, high blood pressure medications, or antidepressants can affect test results. Inform your doctor of any medications you are taking before performing the test.

Trouble sleeping, high stress levels, and strenuous exercise before the test can also influence the results.

Risks of the test

The prolactin test carries little risk of complications. You may have a small bruise where the blood was drawn. Keep pressure on the site for a few minutes after removing the needle to help reduce bruising. You may feel dizzy or lightheaded.

In rare cases, the vein can become inflamed after the test, in a condition known as phlebitis. Treat phlebitis with a warm compress applied to the site several times a day.

You may have ongoing bleeding if you have a bleeding disorder. Also, if you are taking blood-thinning medications such as aspirin or  warfarin , tell your doctor before testing.

Normal results

Your doctor will assess whether your results are normal based on many factors, including your general health. Normal results usually look like the following (ng / mL = nanograms per milliliter):

  • Women in condition: <25 ng / mL.
  • Women who are not in condition: 34 to 386 ng / mL.
  • Men: <15 ng / mL.

 What do elevated prolactin levels mean?

Low prolactin levels are generally not a concern in women or men. However, very high prolactin levels, known as hyperprolactinemia, can indicate a deeper problem. About 10 percent of the population has hyperprolactinemia.

During pregnancy and after delivery, it is normal to have high levels of prolactin in the body. However, hyperprolactinemia can also be caused by anorexia nervosa, liver disease, kidney disease, and hypothyroidism.

Hypothyroidism can cause an enlarged pituitary gland, which is treatable with thyroid hormone replacement therapy. High prolactin levels can also be caused by pituitary tumors. These tumors can be treated medically or surgically.

Certain medications can cause high prolactin levels. Psychiatric drugs such as risperidone and haloperidol can increase their levels. Metoclopramide can also raise your prolactin levels. This medicine is normally used to treat acid reflux or nausea caused by other medicines.

Some common stressors can also raise prolactin levels. These stressors include low blood sugar levels, strenuous exercise activities, and even mild forms of discomfort.

If you find that your prolactin levels are high, you may need to find ways to reduce stress and keep your blood sugar at constant levels.

Red clover, fenugreek, or fennel can raise prolactin levels. Avoid eating anything with these ingredients if you find that you have high prolactin levels.

Prolactin and fertility

In some cases, high prolactin levels can lead to infertility. Prolactinoma tumors can put pressure on the pituitary gland and stop the production of hormones.

This condition is known as hypopituitarism. In men, this causes a lower sex drive and a loss of body hair. In women, it can lead to infertility.

Hyperprolactinemia can make it difficult for a woman to get pregnant. High prolactin levels can disrupt the normal production of the hormones estrogen and progesterone. This can cause the ovaries to release eggs irregularly or to stop completely.

Medications and other prolactinoma treatments help restore fertility in most women. If you find that you have high prolactin levels or prolactinoma tumors, talk to your doctor right away about treatments. You can also ask about removing or shrinking tumors.

Treatment for high prolactin levels

Dopamine agonists such as bromocriptine (Parlodel and Cycloset) are the most common treatment for high prolactin levels. These drugs help the brain make dopamine to control high prolactin levels. They can also shrink prolactinoma tumors.

Your doctor may recommend that you take cabergoline. Cabergoline is a newer prolactinoma treatment with milder side effects than other common prolactinoma medications. Talk to your doctor about cabergoline if you are facing serious side effects from other treatments, including bromocriptine.

Not all prolactin levels will respond well to dopamine agonists. Your doctor may suggest radiation therapy if those medications do not help your prolactin or prolactinoma levels.

Your doctor may suggest surgery if medicine does not reduce its size. Surgery can be done through the nose or upper skull. Surgery and medication together can bring your prolactin levels back to normal.

Other steps you can take to lower prolactin levels include:

  • Changing your diet and keeping your stress levels low.
  • Stop high intensity workouts or activities that overwhelm you.
  • Avoiding activities and clothing that overstimulate your nipples.
  • Take vitamin B-6y vitamin E supplements.

Vitamin B-6 is part of the dopamine production process, and higher levels can lower prolactin levels. Vitamin E naturally prevents increases in prolactin levels. Talk to your doctor or nutritionist before changing your intake of vitamins or other supplements.

Other complications

Your doctor will likely refer you to an endocrinologist if you have a condition related to high prolactin levels. An endocrinologist can guide you through treatment or surgeries.

Your doctor may order an MRI to check if a prolactinoma tumor is causing your prolactin levels to rise. Your doctor will prescribe medications to shrink any existing tumors.

Sometimes there is no specific cause for your high prolactin levels. This is known as idiopathic hyperprolactinemia. It usually goes away without treatment after several months. If your prolactin levels don’t drop, your doctor will likely prescribe medication.

It is possible to get pregnant while receiving treatment for high prolactin levels. If this happens, tell your doctor or endocrinologist right away. You may be asked to stop taking your medicine. However, do not stop taking your medicine until told to do so.

Prolactinoma and hyperprolactinemia are not life threatening. The worst side effects of medications usually go away after treatment.

Infertility caused by high prolactin levels can be reversed once prolactin levels return to normal. Your quality of life will remain high, even if you need long-term treatment.