Prolactin, Serum (Mass Concentration)
This test measures the level of prolactin, a hormone produced by the pituitary gland that regulates milk production and influences other bodily functions.
["Prolactin levels help diagnose hormonal imbalances or conditions affecting milk production and reproductive health."]
Key facts at a glance
- LOINC
- 2842-3
- Short code
- Prolactin SerPl-mCnc
- Synonyms
- Prolactin 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 Is This Test Done?
Your doctor may order a prolactin test to check for conditions like hyperprolactinemia (too much prolactin), which can affect fertility, menstrual cycles, or cause breast changes. It may also be used to evaluate symptoms such as irregular periods, breast tenderness, or unexplained infertility. Sometimes, it’s part of a broader evaluation for pituitary gland disorders or to monitor treatment for conditions like acromegaly or thyroid 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 your blood is drawn early in the morning. Avoid smoking, caffeine, or strenuous activity for a few hours before the draw. If you’re taking medications that affect prolactin levels (like certain antidepressants or antipsychotics), let your doctor know.
What Happens During the Test?
A healthcare provider will insert a needle into a vein in your arm, draw a small amount of blood, and collect it in a tube. The process typically takes a few minutes. You may feel slight discomfort, but it usually goes away quickly. The blood sample is then sent to a lab for analysis.
What Are Possible Results?
Results are compared to a reference range, which can vary slightly by lab. High prolactin levels may suggest conditions like pituitary tumors, kidney problems, or certain medications. Low levels might indicate thyroid issues or other hormonal imbalances. Your doctor will discuss the results in the context of your symptoms and medical history.
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.
◆Associated findings1
Short name
Prolactin
Frequently asked questions
How long does it take to get the results of this test?
Can lifestyle changes, like diet or exercise, affect prolactin levels?
Is this test painful?
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