Prolactin

Prolactin is a hormone produced in the pituitary gland that is known for supporting lactation in women but also has many other functions on immune response, myelin coating on nerves, and enhances LH receptors on testicular Leydig cells so that testosterone can be produced. 

What is Prolactin?

Prolactin is a hormone produced in the pituitary gland that is known for supporting lactation in women but also has many other functions on immune response, myelin coating on nerves, and enhances LH receptors on testicular Leydig cells so that testosterone can be produced. 

Prolactin levels peak during REM sleep and in the early morning. Levels can rise after exercise, meals, sexual intercourse, minor surgical procedures, or epileptic seizures.

In both men and women, the pituitary gland creates the hormone prolactin. In women, it is principally in charge of breastfeeding, some types of breast tissue development, and milk production [3]. Prolactin levels, however, can significantly affect sexual performance in men. The impact of elevated prolactin levels on male sexual performance as well as the ideal prolactin range will be discussed in this article.

Prolactin levels in men are commonly thought to be best between 2 and 18 ng/mL. It is crucial to remember that typical ranges can change based on the facility doing the test. Prolactin levels can change during the day and with specific activities, such exercise, and are typically higher in women than in males [3].

A blood test to determine a man's prolactin levels may be prescribed by his doctor if he is exhibiting signs of elevated prolactin levels, such as sexual dysfunction. More testing could be required to identify the underlying reason if the levels are discovered to be high. Treatment can be required in some situations to lower prolactin levels and enhance sexual function. This may entail taking drugs to reduce prolactin production or having any tumors that may be the reason for the elevated levels removed surgically [2].

In conclusion, men's sexual function can be significantly impacted by excessive prolactin levels. The production of testosterone and other hormones that are crucial for sustaining sexual desire and function can be affected when prolactin levels are too high. Although normal levels can differ depending on the laboratory doing the test, the ideal range for prolactin in men is normally between 2 and 18 ng/mL. A blood test to evaluate prolactin levels and identify the underlying cause may be prescribed by a doctor if a man exhibits signs of excessive prolactin levels.

Normal Prolactin Ranges:

During pregnancy and postpartum lactation, serum prolactin can increase 10- to 20-fold. Exercise, stress, and sleep also cause transient increases in prolactin levels. Consistently elevated serum prolactin levels (>30 ng/mL)indicate hyperprolactinemia in the absence of pregnancy and postpartum lactation. Pituitary adenomas, hypothalamic disease, breast or chest wall stimulation, renal failure, or hypothyroidism can cause prolactin hypersecretion. Several drugs, including many antidepressants, are also common causes of abnormally elevated prolactin levels. Hyperprolactinemia often results in galactorrhea, amenorrhea, infertility in females, and impotence and hypogonadism in males. Renal failure, hypothyroidism, and prolactin-secreting pituitary adenomas are common causes of abnormally elevated prolactin levels.

High Prolactin Consequences

Women are more likely than men to have hyperprolactinemia, or high prolactin levels. However it can arise from a variety of factors in both sexes. Pituitary tumors, prescription drugs, and other underlying medical disorders are a few factors that can contribute to high prolactin levels in men [4]. Men who have high levels of prolactin may have a variety of sexual issues, such as decreased sperm production, erectile dysfunction, and libido loss [5].

Low testosterone production is one of the main ways that excessive prolactin levels have an impact on men's sexual performance. Men's ability to have sexual desire and function is maintained by the hormone testosterone. Prolactin can interfere with the creation of testosterone when levels are too high, which decreases sexual desire and affects erectile function [3].

High prolactin levels can impact the levels of other hormones involved in sexual function in addition to lowering testosterone production. For instance, excessive levels of prolactin can inhibit the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), both of which are crucial for preserving testosterone synthesis and sperm quality in men [3].

High prolactin can decrease testosterone and cause sexual dysfunction.

Low Prolactin Consequences:

However, low prolactin blood levels have also been found to be linked to sexual dysfunction and other issues.  Since prolactin seems involved in immune response and heart muscle integrity, keeping healthy levels is essential.

Prolactinomas are classified as microadenomas (<10 mm) and macroadenomas (>10 mm). Substantial elevation in prolactin (>50 ng/mL) usually indicates a pituitary tumor. Very high levels of prolactin are associated with larger tumors. The finding of a substantial elevation in blood levels of prolactin association with a pituitary lesion more significant than 10 mm by radiographic analysis supports the diagnosis of a macroprolactinoma.

Modest levels of prolactin elevation (25–50 ng/mL) may be associated with several diagnoses. Primary hypothyroidism and chronic renal disease are associated with elevations in prolactin, probably because of altered metabolism or clearance of prolactin. All other causes of hyperprolactinemia should be excluded before a tumor is considered.

Some medications can increase prolactin blood levels in men, as shown in this table (From Ther Clin Risk Manag. 2007 Oct; 3(5): 929–951.)

When to Get the Prolactin Lab Test:

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