Prolactin, Serum (High-Precision, 200 µg/mL Quantification)
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
- 25738-6
- Short code
- Prolactin 2h p 200 ug TRH IV SerPl-mCnc
- Synonyms
- Prolactin 2h p 200 ug TRH IV SerPl-mCnc
- 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 signs of a pituitary tumor. It may also be checked during evaluations for thyroid disorders, certain cancers, or after head injuries.
What to Expect Before the Test
No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the test if instructed. Bring any medications you’re currently taking, as some may affect results. Avoid smoking or drinking alcohol for a few hours before the blood draw.
How the Test Is Done
A healthcare professional will draw blood from a vein in your arm using a small needle. You may feel a slight pinch, but the procedure is quick. The blood sample is sent to a lab for analysis using a sensitive immunoassay method to measure prolactin precisely.
What the Results Mean
Results are compared to a reference range specific to your age, sex, and health status. High prolactin levels may suggest conditions like pituitary tumors, thyroid issues, or certain medications. Low levels could indicate pituitary damage or other hormonal problems. Always discuss your results with your provider.
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 often point to a pituitary adenoma (benign tumor), which can disrupt hormone balance. It may also be linked to medications like antipsychotics or antidepressants, kidney disease, or thyroid disorders. Low prolactin can affect fertility, lactation, and mood regulation. Early diagnosis helps guide treatment, such as medication adjustments or surgery if needed.
Short name
Prolactin Level
Frequently asked questions
How long does it take to get my results?
Can I take my medications before the test?
Does stress affect prolactin test results?
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