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Prolactin, Serum (Mass Concentration)

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 milk production and affects other body functions like mood and sleep.

Quick summary

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

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

Key facts at a glance

LOINC
50521-4
Short code
Prolactin sp5 SerPl-mCnc
Synonyms
Prolactin sp5 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 a prolactin test to check for conditions like hyperprolactinemia (too much prolactin), pituitary tumors, or other hormonal disorders. It might also be used to monitor treatment for conditions such as breast cancer or infertility.

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 or certain antidepressants, let your doctor know.

What Happens During the Test?

A blood sample will be drawn from a vein, typically in your arm. You may feel a slight pinch, but the procedure is quick and usually doesn’t cause discomfort. The sample is then sent to a lab for analysis.

What Are Possible Results?

Results are interpreted based on your individual health, symptoms, and medical history. High prolactin levels may suggest issues like tumors or other pituitary problems, while low levels could indicate conditions like hypothyroidism or pregnancy.

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

How long does it take to get prolactin test results?
Results are typically available within 1 to 3 business days, depending on your lab and healthcare provider’s workflow. Follow-up may be needed if results are outside expected ranges.
Can diet or lifestyle affect prolactin levels?
Certain foods, supplements, or medications (like birth control, antidepressants, or anti-nausea drugs) can influence prolactin levels. Avoiding caffeine, smoking, and certain herbal supplements before testing may help ensure more accurate results.
What if my prolactin test is abnormal?
If your results are abnormal, your doctor may recommend further testing, imaging (like an MRI), or adjustments to your treatment plan. They’ll work with you to determine the best next steps based on your symptoms and medical history.
  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