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Serum Prolactin Level (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 milk production and affects other body 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
12833-0
Short code
Prolactin 20M p chal SerPl-mCnc
Synonyms
Prolactin 20M 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 doctor may order a prolactin test to check for conditions such as pituitary tumors, hormonal imbalances, or issues related to breast milk production. It can also be used to evaluate symptoms like infertility, irregular menstrual cycles, or unexplained headaches.

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 types of exercise. If you’re breastfeeding, let your doctor know, as it may influence results.

During the Test

A healthcare provider will draw blood from a vein in your arm. You may feel a slight pinch, but the process is quick and typically painless. You can usually return to your normal activities immediately afterward.

What the Results Mean

Results are compared to a range of normal values, but since these can vary by lab and individual factors, your doctor will interpret them in the context of your health and symptoms. High or low levels may signal underlying health concerns.

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

Frequently asked questions

What causes prolactin levels to be high?
High prolactin levels (hyperprolactinemia) can result from pituitary tumors, certain medications (like antidepressants or birth control), thyroid issues, or kidney problems. Lifestyle factors, such as stress or sleep deprivation, may also play a role.
How long does it take to get results?
Test results are typically available within a few days to a week, depending on your lab’s processing time. Your doctor will contact you once they have the results.
Can I take anything before the blood draw?
Generally, no special preparation is needed, but avoid smoking or certain medications that might affect results. If you’re unsure, ask your doctor or lab technician for guidance.
  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