Total Serum Prolactin Level (Mass Fraction)
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, including hormones and reproduction.
["Prolactin helps regulate milk production and influences hormones, and abnormal levels may signal health concerns."]
Key facts at a glance
- LOINC
- 50366-4
- Short code
- Prolactin.monomeric/Total MFr SerPl
- Synonyms
- Prolactin.monomeric/Total MFr SerPl
- 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 this test to check for conditions like hyperprolactinemia (high prolactin levels), which can affect fertility, menstrual cycles, or thyroid function. It may also be used to diagnose pituitary tumors, thyroid disorders, or other hormonal imbalances. Sometimes, it’s part of an evaluation for symptoms like irregular periods, breast tenderness, or infertility.
What to Expect Before the Test
No special preparation is needed, but you may be asked to fast for 8–12 hours before the test if instructed. Wear comfortable clothing and bring any medications you’re currently taking. Avoid smoking or drinking alcohol before the blood draw, as they might affect results.
What Happens During the Test?
A healthcare professional will draw blood from a vein in your arm using a small needle. You may feel a slight pinch, but it usually doesn’t cause significant discomfort. The blood sample is then sent to a lab for analysis.
What Are Possible Results?
Results are compared to a range of normal values, but your specific reference range depends on your age, sex, and health status. High or low levels may indicate underlying conditions that need 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 cause symptoms like missed periods, infertility, or galactorrhea (milk production outside of pregnancy). Low levels may suggest pituitary issues or other hormonal disorders. Always discuss results with your provider to understand their meaning in your context.
Short name
Prolactin
Frequently asked questions
What causes prolactin levels to be high?
How long does it take to get results?
Can diet or supplements affect 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