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Serum Prolactin Level (High-Performance Liquid Chromatography/Immunoassay)

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of prolactin, a hormone produced by your pituitary gland, in your blood. Prolactin helps regulate milk production and affects other body functions.

Quick summary

["Prolactin levels can indicate hormonal imbalances or conditions affecting your pituitary gland."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
33907-7
Short code
Prolactin 1h p 200 ug TRH IV SerPl-sCnc
Synonyms
Prolactin 1h p 200 ug TRH IV SerPl-sCnc
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 have symptoms like unexplained breast milk production (galactorrhea) in men, infertility, irregular menstrual periods, or signs of a pituitary tumor. It may also be used to diagnose conditions such as hyperprolactinemia or evaluate certain hormonal disorders.

What to Expect Before the Test

No special preparation is usually needed, but you may be asked to avoid certain medications or activities that could affect hormone levels, such as smoking or certain supplements. Bring any medications you’re currently taking to your appointment.

During the Test

A healthcare professional will draw blood from a vein in your arm. You may feel a slight pinch, but the process is quick and typically painless. The blood sample will be sent to a lab for analysis using a high-performance liquid chromatography (HPLC) or immunoassay method to measure prolactin concentration.

What the Results Mean

Results will show the amount of prolactin in nanograms per deciliter (ng/dL) or another appropriate unit. While reference ranges vary by lab, higher-than-normal levels may suggest conditions like pituitary tumors, certain medications, or hormonal imbalances. Your provider will interpret results in the context of your symptoms and medical history.

Reference range

Adult males: 2-18 ng/mL; Females: 2-29 ng/mLN/A

Specimen: serum

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 Blood Test

Frequently asked questions

What Does It Indicate?
Elevated prolactin levels can signal hyperprolactinemia, which may be caused by pituitary tumors, medications (like antidepressants or antipsychotics), thyroid disorders, or kidney disease. Low levels might be associated with pituitary gland damage or certain genetic conditions. Always discuss results with your healthcare provider for personalized guidance.
How Often Should I Get This Test?
The frequency depends on your symptoms, medical history, and treatment plan. If you’re being monitored for a condition like hyperprolactinemia, your provider may recommend follow-up tests every few months or as needed. Regular check-ups with your healthcare team will help determine the best timing.
Can I Take Anything Before the Test?
Generally, you can eat and drink normally before the test unless instructed otherwise. Avoid smoking or consuming certain supplements that might affect hormone levels, as discussed with your provider. Always follow specific instructions given by your healthcare team or lab staff.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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