Serum Prolactin Test – Indications, Procedures, Results

Last updated: February 8, 2026 Medically reviewed by: RxHarun Orthopedic Specialist Doctor Reading time: 3 min read

PRL; Galactorrhea – prolactin test; Infertility – prolactin test; Amenorrhea – prolactin test; Breast leakage – prolactin test; Prolactinoma – prolactin test; Pituitary tumor – prolactin test

Prolactin is a hormone released by the pituitary gland. The prolactin test measures the amount of prolactin in the blood.

How the Test is Performed

A blood sample is needed .

How to Prepare for the Test

No special preparation is necessary.

How the Test will Feel

When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.

Why the Test is Performed

Prolactin is a hormone released by the pituitary gland The pituitary is a small gland at the base of the brain. It regulates the body’s balance of many hormones.

Prolactin stimulates breast development and milk production in women. There is no known normal function for prolactin in men.

Prolactin is usually measured when checking for pituitary tumors and the cause of:

Breast milk production that is not related to childbirth (galactorrhea)
Decreased sex drive (libido) in men and women
Erection problems in men
Not able to get pregnant (infertility)
Irregular or no menstrual periods ( amenorrhea )

Normal Results

The normal values for prolactin are:

Males: less than 20 ng/dL (425 mIU/L )
Nonpregnant females: 5 to 40 ng/dL (106 to 850 mIU/L)
Pregnant women: 80 to 400 ng/dL (1,700 to 8,500 mIU/L)

Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your doctor about the meaning of your specific test results.

What Abnormal Results Mean

People with the following conditions may have high prolactin levels:

Chest wall injury or irritation
Disease of an area of the brain called the hypothalamus
Thyroid gland does not make enough thyroid hormone ( hypothyroidism )
Kidney disease
Pituitary tumor that makes prolactin (prolactinoma)
Other pituitary tumors and diseases in the area of the pituitary

Certain medicines can also raise prolactin levels, including:

Antidepressants
Butyrophenones
Estrogens
H2 blockers
Methyldopa
Metoclopramide
Phenothiazines
Reserpine
Risperidone
Verapamil

If your prolactin level is high, the test may be repeated in the early morning after an 8-hour fast.

The following can temporarily increase prolactin levels:

Emotional or physical stress (occasionally)
High-protein meals
Intense breast stimulation
Recent breast exam
Recent exercise

Risks

There is very little risk in having your blood taken. Veins and arteries vary in size from one person to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight but may include:

Excessive bleeding
Fainting or feeling lightheaded
Hematoma (blood accumulating under the skin)
Infection (a slight risk any time the skin is broken)

Frequently Asked Questions

Is this article a replacement for a doctor?

No. It is educational content only. Patients should consult a qualified clinician for diagnosis and treatment.

When should I seek urgent care?

Seek urgent care for severe symptoms, rapidly worsening condition, breathing difficulty, severe pain, neurological changes, or any emergency warning sign.

References

Add references, clinical guidelines, textbooks, journal articles, or trusted medical sources here. You can edit this area later with a custom field named _rx_references.

Written by Dr. Harun Ar Rashid, MD - Arthritis, Bones, Joints Pain, Trauma, and Internal Medicine Specialist

Dr. Md. Harun Ar Rashid, MPH, MD, PhD, is a highly respected medical specialist celebrated for his exceptional clinical expertise and unwavering commitment to patient care. With advanced qualifications including MPH, MD, and PhD, he integrates cutting-edge research with a compassionate approach to medicine, ensuring that every patient receives personalized and effective treatment. His extensive training and hands-on experience enable him to diagnose complex conditions accurately and develop innovative treatment strategies tailored to individual needs. In addition to his clinical practice, Dr. Harun Ar Rashid is dedicated to medical education and research, writing and inventory creative thinking, innovative idea, critical care managementing make in his community to outreach, often participating in initiatives that promote health awareness and advance medical knowledge. His career is a testament to the high standards represented by his credentials, and he continues to contribute significantly to his field, driving improvements in both patient outcomes and healthcare practices. Born and educated in Bangladesh, Dr. Rashid earned his BPT from the University of Dhaka before pursuing postgraduate training internationally. He completed his MD in Internal Medicine at King’s College London, where he developed a special interest in inflammatory arthritis and metabolic bone disease. He then undertook a PhD in Orthopedic Science at the University of Oxford, conducting pioneering research on cytokine signaling pathways in rheumatoid arthritis. Following his doctoral studies, Dr. Rashid returned to clinical work with a fellowship in interventional pain management at the Rx University School of Medicine, refining his skills in image-guided joint injections and minimally invasive pain-relief techniques.