Prolactin is a hormone produced by the pituitary gland majorly responsible for lactation (production of milk in the body). Prolactin is produced in people in small amounts that contribute to bodily processes. The level of prolactin increases in the body after child birth to produce milk for breastfeeding. Prolactin also helps in the development of breasts and maintains the menstrual cycle. It can also helps with sperm production. An imbalance in prolactin production in the body can cause problems and needs medical help.