What is prolactin?
Prolactin is a hormone produced by the pituitary gland. The pituitary is a small organ at the base of the brain. Prolactin’s main function is to produce milk after childbirth. It is also linked with fertility, menstruation, fat metabolism, fluid regulation, and sexual satisfaction in both men and women. An abnormal level does not necessarily signify a problem if you have no symptoms.
Why test prolactin?
Prolactin testing is important for diagnosing various conditions, as elevated prolactin levels can lead to symptoms like unexplained breast milk flow, abnormal nipple discharge, absence of menstrual periods, infertility in women, and decreased libido or erectile dysfunction in men. It is included in fertility assessments and is often used as a follow-up test in men with low testosterone. Additionally, prolactin levels are monitored to detect the recurrence of prolactin-secreting tumours (prolactinomas).
What do the results mean?
Prolactin levels are normally low in men and non-pregnant women. Levels increase during pregnancy and in a variety of health conditions.
What causes low prolactin levels?
Prolactin levels are normally low in men and non-pregnant women. Low prolactin does not usually need medical treatment. Consult your doctor if your level is lower than the reference range. Consult a nutritionist for dietary and lifestyle advice.
What causes high prolactin levels?
High levels of prolactin are normal during pregnancy and whilst breastfeeding. High levels may also be associated with hypothyroidism, extreme exercise, birth control pills, pituitary tumours, polycystic ovary syndrome (PCOS), eating disorders and a variety of health conditions. Stress can also temporarily increase prolactin, especially in men. We recommend sitting down for 15 minutes before testing prolactin.
Other information
High levels of prolactin can lead to insulin resistance. Women of childbearing age tend to have higher prolactin levels than men, and the level varies with the menstrual cycle. Stress caused by illness, chest trauma, seizures, lung cancer, nipple stimulation, and marijuana use may mildly elevate prolactin.
Some medications elevate prolactin. These include estrogen, tricyclic antidepressants, risperidone, opiates, amphetamines, hypertension drugs (reserpine, verapamil, methyldopa), and medicines used to treat gastroesophageal reflux (cimetidine). Medications that can lower prolactin levels include dopamine, levodopa, and ergot alkaloid derivatives.
Preparations for this test
If possible, avoid alcohol for the day before the test.
On the day of the test
Always take I.D. with you when going to take a test. Take this test before 10 am, as results can vary throughout the day. Arrive in good time and sit quietly for 15 minutes before taking the test.