Prolactin is a hormone produced by the pituitary gland in both men and women. This hormone is best-known for its role during pregnancy and breastfeeding when levels rise to up to 20 times higher than normal due to its role in producing breast milk. Non-pregnant women and men also produce prolactin, but in these situations, the hormone’s function is not as well understood. Prolactin levels also fluctuate throughout the day, and are higher during sleep, just after awakening and during times of emotional or physical stress.
Prolactin is also released after orgasm. Some researchers believe that this phenomenon causes the sexual refractory period, or the period after orgasm during which it is difficult or impossible to become aroused again. This may explain part of the connection between prolactin and libido: Prolactin may be released even outside of sexual situations, impeding the body’s ability to become aroused later.
Prolactin has been studied to some extent in animals, as well. Some research suggests that prolactin is associated with feelings of despair and fear in monkeys. Researchers found that monkey’s prolactin levels rise after being trapped in a cage. In general, more research is needed in relation to this hormone in order to fully understand all of its functions in both animals and humans.
High Prolactin and Libido
Higher-than-average prolactin, also called hyperprolactinemia, often decreases sex drive. According to Alan Wein, chair of the Division of Urology at the University of Pennsylvania School of Medicine, hyperprolactinemia is responsible for some cases of male infertility and erectile dysfunction. This may be because prolactin can decrease levels of sex hormones like testosterone in men and estrogen in women. These sex hormones play a big role in maintaining a healthy libido.
The causes of high prolactin levels aren’t entirely understood, but researchers have been able to point to certain drugs, pituitary tumors, hypothyroid disease and vitamin B6 deficiency as possible causes. A vitamin B6 deficiency can be treated and prevented by consuming a diet with plenty of B6-rich foods, which include potatoes, bananas, salmon, spinach and chicken. Getting plenty of zinc is also thought to lower prolactin levels. Some examples of zinc-rich foods are shellfish, beef, beans and turkey.
Effects of Low Prolactin
Low prolactin levels can also cause a decrease in libido. One study published in the Journal of Sexual Medicine showed evidence of a connection. The study involved nearly 3,000 men between the ages of 40 and 79. Researchers measured participants’ hormone levels, BMIs, cholesterol and blood sugar. The men also answered questions about their health, lifestyle and libido. The researchers found that men with lower-than-average prolactin levels were more likely to have high BMI, high blood sugar, more symptoms of depression and poorer sexual health.
The researchers say that the study does not prove a direct cause-and-effect relationship between prolactin and libido, but rather an association that needs more research to be fully understood. Low prolactin may directly cause low libido, low prolactin levels may be a symptom of something else causing low libido, or low prolactin levels and lower sex drive may both be caused by overall poor health.
Because prolactin is thought to be released after orgasm, one simple solution to low prolactin levels is to have orgasms more frequently. However, this only holds true for partnered sex; orgasm from masturbation has been found to release little to no prolactin.
If you suspect you may have abnormally-high or abnormally-low prolactin, your doctor can do a blood test. If your prolactin levels are abnormal, he or she may wish to check your pituitary gland and thyroid function.