Skip to content

Prolactin, Serum (Mass Concentration)

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.

Quick summary

["Prolactin levels can help diagnose hormonal imbalances or conditions affecting your pituitary gland or reproductive system."]

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

Key facts at a glance

LOINC
49220-7
Short code
Prolactin SerPl 3rd IS-mCnc
Synonyms
Prolactin SerPl 3rd IS-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
rd-is
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 doctor may order a prolactin test to check for conditions like hyperprolactinemia (high prolactin levels), which can cause issues with fertility, menstrual problems, or breast milk production. It may also be used to evaluate symptoms such as headaches, vision changes, or hormonal imbalances that could be linked 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 dopamine agonists (e.g., for Parkinson’s or prolactin-related conditions), let your doctor know before testing.

What Happens During the Test?

A blood sample will be taken from a vein, typically in your arm. You may feel a small pinch, but it usually doesn’t cause discomfort. The sample is then sent to a lab for analysis.

What Are Possible Results?

Results are compared to standard ranges, but your actual values will depend on your health, age, and other factors. High or low levels may signal underlying health concerns that need further evaluation.

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 Prolactin Level Mean?
Elevated prolactin can be caused by conditions like pituitary tumors, certain medications (e.g., antidepressants, antipsychotics), or thyroid disorders. It may lead to infertility, irregular periods, or galactorrhea (milk production outside pregnancy). Your doctor will review your symptoms and test results to determine the cause.
What Does a Low Prolactin Level Mean?
Low prolactin is less common but may occur with certain pituitary or brain injuries, hormonal imbalances, or pregnancy. It could affect milk production in breastfeeding mothers or reproductive health. Further testing may be needed to identify the reason.
How Often Should I Get This Test?
Your doctor will decide how often you need retesting based on your symptoms, medical history, and treatment plan. Follow-up tests may be scheduled if your levels are abnormal or if you’re undergoing treatment for a condition linked to prolactin.
  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