Prolactin in men plays an important role in processes like regulating testosterone production, healthy sperm production, and reducing stress and anxiety.

Prolactin is a hormone produced by the pituitary gland in the brain and is normally associated with breast milk production in women and people assigned female at birth (AFAB).

In some cases, prolactin levels can be elevated in men and people assigned male at birth (AMAB), causing symptoms like low libido, erectile dysfunction, and abnormal breast growth. These symptoms should be evaluated by an endocrinologist who can run tests and determine the most appropriate treatment.

Main functions

Prolactin in men plays a role in the following functions:

Regulating the production of testosterone;
Maintaining healthy sperm production;
Regulating the immune system;
Regulating the metabolism;
Stimulating the formation of new neurons;
Reducing stress and anxiety.

Normal levels of prolactin in men are therefore important for maintaining a healthy body.

Where it is produced

Prolactin is produced by the pituitary gland, which is located in a region at the base of the brain called the sella turcica.

The pituitary gland is directly attached to the hypothalamus, which controls the production of the majority of pituitary hormones, including prolactin.

Indications for testing

A blood test to check prolactin levels in men is typically indicated for the following:

Low libido;
Erectile dysfunction;
Infertility;
Mood changes or depression;
Breast growth (known as gynecomastia);
Leaking milk from the nipples (rare).

These symptoms are most typical of high prolactin in men.

Other less common symptoms include headache, vision changes related to atrophy of the optic nerve, and cranial nerve palsy.

Reference values

The normal level of prolactin in men is less than 20 ng/mL, which can be checked on a simple blood test. Reference ranges may vary based on the lab that is performing the test.

If results reveal a high level of prolactin, or hyperprolactinemia, an endocrinologist may order additional tests to help identify a cause.

Exams like an MRI (magnetic resonance imaging) or CT scan (computerized tomography) of the pituitary may also be indicated.

Preparing for the test

A simple blood test can be done to check prolactin levels, which may be ordered if a man presents with symptoms of high prolactin or has certain health problems that can affect prolactin production.

For this test, it is recommended to have your blood drawn in the morning, as prolactin levels can vary throughout the day.

It is also recommended to avoid intense physical exercise and stressful activities right before the test, as this can cause a temporary elevation in prolactin levels.

Causes of high prolactin

High levels of prolactin in men may be caused by:

A pituitary tumor called a prolactinoma;
Certain medications, such as antidepressants, antiemetics, antiepileptics, or anti-hypertensives;
Chronic stress;
Hypothyroidism.

High prolactin may also be a symptom of other conditions like sarcoidosis, tuberculosis, aneurysm, kidney disease, or cirrhosis of the liver.

Causes of low prolactin

Low prolactin levels in men are generally not concerning, since men do not usually produce as high amounts of this hormone as women do.

However, low prolactin in men does appear to affect sperm quality and weaken the immune system.

Treatment options

Treatment for high prolactin is managed by an endocrinologist and varies based on the degree of elevation.

In the case of high prolactin caused by medication, your doctor may recommend changing the dose or suspending use of that medication, or prescribe a different medication altogether.

If the cause of elevated prolactin levels is a tumor, medications like cabergoline or bromocriptine may be prescribed. Surgery may also be indicated in the case of a large tumor or a tumor that is growing in size.

Treatment for low prolactin typically involves regular follow with your doctor or primary care provider to monitor levels of prolactin and other hormones.