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Prolactin, Serum (Mass Concentration) – Confirmatory Immunoassay

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

This test measures the amount of prolactin, a hormone produced by your pituitary gland, in your blood. It helps assess conditions like hyperprolactinemia or potential pituitary tumors.

Quick summary

["Prolactin levels can affect fertility, menstrual cycles, and other hormonal functions—this test helps diagnose potential hormonal imbalances."]

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

Key facts at a glance

LOINC
108835-0
Short code
Macroprolactin Msmt SerPl
Synonyms
Macroprolactin Msmt SerPl
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 This Test Is Done

Your doctor may order this test if you have symptoms like irregular periods, infertility, breast milk production outside pregnancy, or signs of a pituitary issue. It may also be used to confirm or monitor prolactin levels after initial screening.

What to Expect Before the Test

No special preparation is needed, but you may be asked to avoid certain medications or activities that could affect results. For example, smoking or certain drugs might influence hormone levels.

How the Test Works

A blood sample is drawn from a vein, usually in your arm. The sample is then analyzed using an immunoassay method to measure prolactin concentration.

Possible Results and Interpretation

Results are compared to general reference ranges, but individual ranges may vary. Elevated levels may suggest conditions like pituitary tumors or certain medications. Lower-than-expected levels could indicate rare hormonal deficiencies.

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 Confirmation

Frequently asked questions

What causes prolactin levels to be high?
High prolactin levels can result from pituitary tumors, certain medications (like antipsychotics or birth control), stress, or thyroid disorders. Lifestyle factors like smoking or pregnancy may also play a role.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on your lab’s processing time. Your doctor will contact you once they’re ready.
Can I take anything before the test?
No specific prep is needed, but avoid smoking or certain medications that might affect hormone levels. Follow your doctor’s instructions if you have any concerns.
  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