Prolactin (Serum or Plasma) by Immunoassay
This test measures the amount of prolactin, a hormone produced by the pituitary gland, in your blood. It helps evaluate conditions affecting hormone balance, fertility, or reproductive health.
["Prolactin levels can signal potential hormonal imbalances or medical conditions."]
Key facts at a glance
- LOINC
- 12830-6
- Short code
- Prolactin sp9 p chal SerPl-mCnc
- Synonyms
- Prolactin sp9 p chal 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 This Test Might Be Ordered
Your healthcare provider may recommend this test if you experience symptoms like irregular menstrual cycles, infertility, unexplained headaches, or signs of high prolactin levels (such as breast milk production outside of pregnancy or nursing). It may also be used to monitor treatment for conditions like pituitary tumors or hyperprolactinemia.
What to Expect Before the Test
No special preparation is usually needed, but you may be asked to avoid certain medications (like some antidepressants or antipsychotics) that could affect results. If you're breastfeeding, let your provider know, as this may influence testing timing.
How the Test Is Performed
A blood sample is drawn from a vein, typically in your arm. The sample is then sent to a lab for analysis using an immunoassay method to detect prolactin levels.
What the Results Mean
Results are reported in nanograms per milliliter (ng/mL) or picograms per milliliter (pg/mL). While reference ranges vary by lab, elevated levels may indicate conditions like pituitary tumors, thyroid disorders, or certain medications. Lower-than-normal levels might suggest rare pituitary 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.
Clinical Significance
Short name
Prolactin Level
Frequently asked questions
Prolactin levels are crucial for diagnosing conditions such as hyperprolactinemia (high prolactin), which can interfere with fertility, cause menstrual irregularities, or lead to galactorrhea (milk production outside pregnancy). Low prolactin can sometimes signal pituitary dysfunction or other hormonal imbalances.
If your provider prescribed medications known to affect prolactin levels (e.g., certain antidepressants or antipsychotics), you may need to stop them temporarily or adjust timing. Always follow your healthcare provider’s instructions. If you’re breastfeeding, discuss timing with your provider to ensure safety and accuracy.
You can eat and drink normally unless instructed otherwise. Some tests may require fasting, but prolactin testing does not typically require dietary restrictions.
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