Prolactin, Serum
This test measures the amount of prolactin, a hormone produced by the pituitary gland, in your blood. It helps evaluate conditions related to hormone imbalance, reproductive health, or potential pituitary disorders.
["Prolactin levels can indicate hormonal imbalances or health issues affecting your reproductive system or pituitary function."]
Key facts at a glance
- LOINC
- 20568-2
- Short code
- Prolactin SerPl IA-mCnc
- Synonyms
- Prolactin SerPl IA-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
- Method
- ia
- 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 diagnose or monitor conditions such as infertility, irregular menstrual cycles, breast pain or discharge, high blood pressure, or symptoms of a pituitary tumor. It may also be used to check for hormonal imbalances or to assess the effectiveness of treatments for conditions like hyperprolactinemia.
What to Expect Before the Test
No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test if your blood is drawn early in the morning, as prolactin levels can fluctuate throughout the day. Avoid smoking or strenuous activity before the test.
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 brief pinch, but the procedure is quick and typically painless. The blood sample is then sent to a lab for analysis.
What Are Possible Results?
Results are interpreted based on your age, sex, and overall health. High prolactin levels may suggest conditions like a pituitary tumor, thyroid issues, or certain medications affecting hormone production. Low levels might indicate pituitary damage or other hormonal deficiencies.
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 such as missed periods, infertility, galactorrhea (milk production in non-nursing individuals), or reproductive problems. Low levels may lead to hormonal imbalances, affecting growth, metabolism, or sexual function. Regular monitoring is important if you have a history of pituitary disorders or take medications that influence prolactin.
Short name
Prolactin Level
Frequently asked questions
What Causes High Prolactin Levels?
What Causes Low Prolactin Levels?
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