Prolactin, Serum or Plasma Concentration (Immunoassay)
This test measures the amount of prolactin, a hormone produced by your pituitary gland, in your blood. Prolactin helps regulate breast milk production and affects other body functions like mood and sleep.
["Prolactin levels can help diagnose hormonal imbalances or conditions affecting your pituitary gland."]
Key facts at a glance
- LOINC
- 111053-5
- Short code
- Prolactin Msmt SerPl
- Synonyms
- Prolactin Msmt SerPl
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 2
- Ref high
- 18
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 84146
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may recommend this test if you have symptoms like unexplained breast milk production in men, irregular menstrual periods, infertility, headaches, or vision changes. It could also be done to monitor conditions like pituitary tumors or certain medications that affect prolactin levels.
What to Expect Before the Test
No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if it involves a blood draw, but this is not always required for prolactin testing. Avoid strenuous exercise or smoking right before the test, as these can temporarily raise prolactin levels.
What Happens During the Test
A healthcare professional will draw blood from a vein in your arm. You may feel a slight pinch, but the procedure is quick and typically painless. The blood sample is then sent to a lab for analysis using an immunoassay method to measure prolactin concentration.
What the Results Mean
Results are reported as a concentration in nanograms per milliliter (ng/mL) or picograms per milliliter (pg/mL). While reference ranges vary by lab, very high or very low levels may signal underlying health concerns that need further evaluation.
Reference range
Adult males: 2-18 ng/mL; Females: 2-29 ng/mLN/A
For females: inform if menstrual cycle status. For certain tests, timing within menstrual cycle may matter.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated prolactin levels may indicate conditions like pituitary adenomas, kidney disease, or certain medications. Low levels could suggest hypothyroidism, pregnancy, or other hormonal imbalances. Your provider will discuss results in the context of your symptoms and medical history.
Short name
Prolactin Level
Frequently asked questions
How long does it take to get prolactin test results?
Can prolactin levels change based on my activities?
What if my prolactin level is outside the normal range?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy