Prolactin is a polypeptide hormone, also known as prolactin (PRL), which is one of the hormones secreted by the pituitary gland. There are still many factors that cause the increase of male prolactin, which are generally caused by physiological factors, certain drugs, hypothalamic lesions, and pituitary lesions. When men have hyperprolactinemia, they usually show hypogonadism, erectile dysfunction, decreased sperm count, decreased sperm motility, and even more infertility and osteoporosis.