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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 your pituitary gland, in your blood serum. Prolactin helps regulate milk production in women and may influence other body functions like mood and sleep.

Quick summary

["Prolactin helps regulate milk production and may affect mood and sleep; abnormal levels can signal health concerns."]

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

Key facts at a glance

LOINC
12829-8
Short code
Prolactin sp8 p chal SerPl-mCnc
Synonyms
Prolactin sp8 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 like hyperprolactinemia (high prolactin levels), which can cause issues such as infertility, irregular menstrual cycles, or breast changes. It may also be used to evaluate symptoms like headaches, vision problems, or unexplained galactorrhea (milk discharge from nipples). Sometimes, it’s part of a workup for pituitary gland disorders or to monitor treatment for conditions like acromegaly or thyroid disorders.

What to Expect Before the Test

No special preparation is usually needed. You may be asked to fast for 8–12 hours before the test, but always follow your doctor’s instructions. Wear comfortable clothing and plan to stay near the testing site for a short time, as the blood draw typically takes just a few minutes.

What Happens During the Test?

A healthcare professional will insert a small needle into a vein in your arm. You may feel a slight pinch, but the procedure is quick. Blood will be drawn into a tube, and you’ll be able to resume normal activities immediately afterward. If you experience dizziness or lightheadedness, let the provider know.

What Are Possible Results?

Results are compared to a general range of what’s considered normal for adults, though individual ranges can vary. High prolactin levels may suggest issues with your pituitary gland or other hormonal imbalances. Low levels might indicate conditions like hypothyroidism or certain medications affecting hormone production.

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.

High prolactin levels can cause symptoms like missed periods, infertility, or breast tenderness in women, and may lead to reduced sperm count or erectile dysfunction in men. It can also contribute to headaches or vision changes if the pituitary gland is affected. Low prolactin levels are less common but may signal underlying thyroid or pituitary issues. Always discuss results with your doctor for personalized interpretation.

Short name

Prolactin Level

Frequently asked questions

How long does it take to get my prolactin test 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 to review the results with you.
Can I take anything before or after the blood draw?
No special foods or liquids are restricted unless instructed otherwise, but avoid caffeine or heavy meals right before the test. After the draw, you can resume your normal activities, though mild bruising or soreness at the site is normal.
What if my prolactin level is outside the normal range?
If your results are abnormal, your doctor may recommend further testing or evaluation, such as additional hormone checks or imaging studies (like an MRI) to identify the underlying cause. Follow-up may include monitoring symptoms or adjusting medications if applicable.
  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