prolactin

Prolactin is a hormone best known for helping mammals produce milk after giving birth. But it does more than support milk production. It is also involved in reproduction and may affect immune function and behavior. Think of it as one of the body's helpers during pregnancy and breastfeeding. Its levels naturally rise during these times, but stress, sleep, and some medicines can also change them. A doctor might check your levels if you have irregular periods, unexpected milk discharge, or fertility problems.

Imagine a mother caring for her newborn. This hormone helps the body prepare to nourish new life. Men also produce it, usually at lower levels, and changes in those levels can sometimes affect health.

Prolactin is a protein hormone produced mainly by the pituitary gland, a small organ at the base of the brain. It is best known for its role in lactation, or milk production, after childbirth, but its effects are broader than that. It is an important part of the body's reproductive system in both women and men.

In women, prolactin helps prepare the breasts for milk production during pregnancy and supports milk supply after delivery. High levels can also reduce ovulation during breastfeeding, which is one reason fertility may be lower at that time. However, abnormally high levels, a condition called hyperprolactinemia, can cause irregular or absent menstrual cycles, infertility, and sometimes bone loss over time.

In men, prolactin is usually present at lower levels. When those levels become too high, they can be linked to problems such as low sex drive, erectile dysfunction, infertility, and sometimes enlarged breast tissue, called gynecomastia.

This hormone is not only about reproduction. It also appears to affect the immune system, and research suggests it may play a part in parental behavior and social bonding in some species. Stress, lack of sleep, certain medicines, and some medical conditions can all change prolactin levels. Because of that, doctors often measure it with a blood test when looking into reproductive problems, unexpected milk production, or other hormone-related concerns.

So, while milk production may be the first thing that comes to mind, prolactin is better understood as a hormone with several roles in reproduction and other body systems. It works quietly in the background, but it can matter a great deal when the body's hormone balance changes.