Prolactrine

Prolactin (PRL) is a peptide hormone primarily associated with lactation. In breastfeeding, the infant suckling the teat stimulates the production of prolactin, which fills the breast with milk (lactogenesis) in preparation for the next feed. Oxytocin, a similar hormone, is also released, which triggers milk let-down.f

A prolactin test measures the level of the hormone prolactin, which is made by the pituitary gland, in your blood.

Pregnant women have high levels of prolactin, which helps make breast milk. During pregnancy, prolactin levels increase by 10 to 20 times. After the baby is born, prolactin stays high if you are breast-feeding. In women who do not breast-feed, prolactin levels return to normal soon after they give birth. After months of breast-feeding, prolactin levels may also return to normal levels even if you still breast-feed.

Prolactin levels are different throughout the day. The highest levels occur during sleep and shortly after you wake up. Prolactin levels also get higher during times of physical or emotional stress.

Many medicines can cause prolactin levels to go up. Tumors of the pituitary gland can sometimes cause prolactin to be made. A damaged pituitary gland may not be able to make normal amounts of prolactin so levels will be lower.