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Prolactin, Serum

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 breast milk production and affects other body functions, including reproduction and bone health.

Quick summary

["Prolactin levels can help diagnose 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
15081-3
Short code
Prolactin SerPl-aCnc
Synonyms
Prolactin SerPl-aCnc
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 Might This Test Be Done?

Your healthcare provider may order a prolactin test to check for conditions like hyperprolactinemia (too much prolactin), which can cause issues such as irregular menstrual periods, infertility, or galactorrhea (milk production outside of pregnancy). It may also be used to evaluate symptoms like headaches, vision changes, or unexplained weight gain that could relate to pituitary gland problems.

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 results, such as smoking or certain supplements. If you’re taking medications like birth control pills, antidepressants, or antipsychotics, let your provider know.

What Happens During the Test?

A blood sample will be drawn from a vein, typically in your arm. This is a quick and usually painless procedure. You may feel a slight pinch or discomfort, but it should only last a few seconds.

What Are Possible Results?

Results are interpreted by your healthcare provider based on your symptoms, medical history, and other tests. There are no standard reference ranges provided here, as they can vary by lab and individual factors.

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.

◆Associated findings1

Short name

Prolactin Level

Frequently asked questions

What Does a High or Low Prolactin Level Mean?
Elevated prolactin levels may indicate conditions like pituitary tumors, kidney disease, or certain medications that affect hormone production. Low levels might suggest pituitary damage or other hormonal imbalances. Always discuss results with your provider for personalized interpretation.
How Often Should I Get This Test?
Your provider will determine the frequency based on your health needs. Some people may need follow-up tests if initial results are abnormal or if symptoms persist.
Can I Take Anything Before or After the Test?
Typically, you can eat and drink normally before the test. Avoid smoking or consuming certain supplements that might influence hormone levels. Follow your provider’s specific instructions if you’re on medications that could affect results.
  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