Serum Prolactin Level
This test measures the amount of prolactin, a hormone produced by the pituitary gland, in your blood. Prolactin helps regulate breast milk production and affects other body functions.
["Prolactin levels can help diagnose conditions affecting hormone balance or reproductive health."]
Key facts at a glance
- LOINC
- 25737-8
- Short code
- Prolactin 20M p 200 ug TRH IV SerPl-mCnc
- Synonyms
- Prolactin 20M 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 Might This Test Be Ordered?
Your healthcare provider may recommend a prolactin test if you have symptoms like irregular menstrual periods, infertility, breast tenderness, or signs of hormonal imbalances. It may also be used to evaluate conditions such as pituitary tumors or other pituitary disorders.
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 by your provider. Wear comfortable clothing and plan to stay near the testing site for a short time.
How the Test Is Performed
A healthcare professional will draw blood from a vein in your arm using a small needle. You may feel a brief pinch, but the procedure is quick and typically painless. The blood sample is then sent to a lab for analysis.
What the Results Mean
Results are compared to standard reference ranges, but they can vary by lab. High prolactin levels may suggest conditions like pituitary tumors, thyroid issues, or certain medications affecting hormone production. Low levels may indicate rare pituitary disorders.
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 can interfere with normal hormone function, leading to fertility problems, menstrual irregularities, or breast changes. Low levels are less common but may signal pituitary dysfunction or other underlying health concerns. Always discuss results with your provider for personalized interpretation.
Short name
Prolactin
Frequently asked questions
What causes prolactin levels to be abnormally high?
How long does it take to get prolactin test results?
Can lifestyle changes 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