Prolactin (Serum or Plasma)
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 helps control breast milk production and influences reproductive and non-reproductive behaviors."]
Key facts at a glance
- LOINC
- 10507-2
- Short code
- Prolactin Ag Tiss Ql ImStn
- Synonyms
- Prolactin Ag Tiss Ql ImStn
- 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
- Method
- immune-stain
- 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 (too much prolactin), which can affect fertility, menstrual cycles, or cause symptoms like breast tenderness or missed periods. It may also be used to evaluate pituitary gland function or diagnose conditions like tumors or thyroid disorders that can influence hormone levels.
What to Expect Before the Test
No special preparation is needed, but you may be asked to fast for 8–12 hours before the blood draw if your test includes a glucose measurement. Wear comfortable clothing and arrange for someone to drive you home if you’ve had alcohol or sedatives recently.
During the Test
A healthcare professional will insert a small needle into a vein in your arm. You may feel a brief pinch, but the procedure is quick. Blood is collected into a tube, and the site is cleaned and bandaged afterward.
Possible Results and Next Steps
Results are typically reported as a concentration of prolactin in nanograms per milliliter (ng/mL). Your provider will compare your result to your clinical picture and may recommend follow-up tests, such as imaging (like an MRI) or additional hormone checks if needed. High or low prolactin levels may prompt 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 can indicate conditions like pituitary adenomas (benign tumors), thyroid disorders, kidney problems, or medications that affect hormone production. Low prolactin may suggest pituitary damage, pregnancy, or certain medications. Always discuss results with your provider, as they consider your symptoms, medical history, and other test results for accurate interpretation.
Short name
Prolactin Level
Frequently asked questions
What causes prolactin levels to be abnormally high?
What symptoms might prolactin levels affect?
How often should I get this test?
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