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Serum Prolactin Level (Quantitative)

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

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

Quick summary

["Prolactin levels can help diagnose hormonal imbalances or conditions like hyperprolactinemia."]

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

Key facts at a glance

LOINC
12834-8
Short code
Prolactin 15M p chal SerPl-mCnc
Synonyms
Prolactin 15M 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 Is This Test Done?

Your healthcare provider may order this test to check for conditions affecting hormone production, such as pituitary tumors, thyroid disorders, or issues related to breast milk production. It may also be used to monitor treatment for conditions like hyperprolactinemia.

What to Expect Before the Test

No special preparation is needed for this blood test. You may have a small needle inserted into a vein in your arm to draw blood. It usually takes a few minutes.

What to Expect During the Test

You’ll likely feel a slight pinch when the needle is inserted, but most people describe it as minimal discomfort. The area may feel sore for a short time afterward.

Possible Results and Interpretation

Results are compared to a general reference range for healthy adults. High levels may suggest conditions like pituitary tumors or certain medications. Low levels might indicate thyroid issues or other hormonal imbalances.

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.

Elevated prolactin levels can indicate hyperprolactinemia, which may be caused by pituitary tumors, kidney problems, or certain medications. Low levels may signal thyroid dysfunction or other hormonal disorders. Regular monitoring is important for patients on medications that affect prolactin.

Short name

Prolactin

Frequently asked questions

What causes prolactin levels to be high?
High prolactin levels can result from conditions like pituitary adenomas, kidney disease, or certain medications (e.g., antipsychotics, antihypertensives). Stress, pregnancy, and breastfeeding can also temporarily raise prolactin.
How often should I get this test?
Your doctor will determine how often you need this test based on your symptoms, medical history, and treatment plan. Follow-up tests may be scheduled more frequently if you’re being monitored for conditions like hyperprolactinemia.
Can diet or lifestyle affect prolactin levels?
While diet and lifestyle factors like stress, exercise, and sleep can influence hormone levels, they do not typically cause significant fluctuations in prolactin levels on their own. Always discuss any concerns with your healthcare provider.
  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