Prolactin, Serum
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 bodily functions.
["Prolactin levels can help diagnose hormonal imbalances or conditions affecting your pituitary gland."]
Key facts at a glance
- LOINC
- 33909-3
- Short code
- Prolactin 2h p 200 ug TRH IV SerPl-sCnc
- Synonyms
- Prolactin 2h p 200 ug TRH IV SerPl-sCnc
- 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 Is This Test Done?
Your healthcare provider may order a prolactin test to check for conditions like hyperprolactinemia (high prolactin levels), which can cause issues such as infertility, irregular menstrual cycles, or problems with milk production. It may also be used to evaluate symptoms like headaches, vision changes, or unexplained weight gain that could be linked to pituitary gland 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 it involves drawing blood from a vein. Let your provider know about any medications you’re taking, as some can affect prolactin levels.
How the Test Is Performed
A healthcare professional will insert a needle into a vein in your arm to draw blood. You may feel a small pinch, but the procedure is quick. The blood sample is then sent to a lab for analysis.
What the Results Mean
Results are compared to standard reference ranges, but exact values can vary by lab. High prolactin levels may indicate conditions like pituitary tumors, thyroid issues, or certain medications. Low levels might suggest rare disorders or pregnancy.
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 disrupt normal hormone function, leading to fertility problems, menstrual irregularities, or symptoms like breast tenderness. Low levels are less common but may signal underlying hormonal or thyroid disorders. Always discuss results with your provider for personalized interpretation.
Short name
Prolactin Level
Frequently asked questions
How long does it take to get prolactin test results?
Can I take anything before my prolactin test?
What are common causes of high prolactin levels?
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