Clinical Significance

The primary physiological function of PRL is to stimulate and maintain lactation in women. In normal females, serum PRL levels generally range from 1-25 ng/mL (ug/L) while normal male levels typically range from 1-20 ng/mL (ug/L). Normal PRL secretions varies with time which results in serum PRL levels 2-3 times higher at night than during the day. The biological half-life of PRL is approximately 20-50 minutes. Serum PRL levels during the menstrual cycle are variable and commonly exhibit slight elevations during the mid-cycle. Prolactin levels in normal individuals tend to rise in response to physiological stimuli including: sleep, exercise, nipple stimulation, sexual intercouse, hypoglycemia, pregnancy, and surgical stress.

Prolactin is secreted by the anterior pituitary gland and is required for normal breast development and lactation in women. Elevated PRL levels may be detected during the eighth week of pregnancy with levels continuing to rise throughout gestation. In the absence of breast feeding, PRL levels return to normal within three weeks after birth. Abnormally high levels of PRL are often associated with female infertility, impotence and infertility in men, primary hypothyroidism, and pituitary tumors.

_{Source: Access Prolactin IFU #33530,  12/16/16}