Prolactin (Serum) by Immunoassay
This test measures the amount of prolactin, a hormone produced by the pituitary gland, in your blood. Prolactin helps regulate breast milk production and affects other bodily functions.
["Prolactin helps control breast milk production and influences other hormones in your body."]
Key facts at a glance
- LOINC
- 19251-8
- Short code
- Prolactin p chal SerPl-mCnc
- Synonyms
- Prolactin 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 (too much prolactin), which can cause issues such as infertility, irregular menstrual periods, or problems with milk production. It may also be used to evaluate symptoms like headaches, vision changes, or signs of hormonal imbalances. Sometimes, it’s part of a broader evaluation for pituitary gland disorders or to monitor treatment for conditions like acromegaly or prolactinoma (a benign tumor affecting prolactin levels).
What to Expect Before the Test
No special preparation is needed for this blood test. You may be asked to fast for a few hours before your blood is drawn, but your doctor will let you know if that applies. Avoid smoking or drinking alcohol for at least 30 minutes before the test if instructed. If you’re taking certain medications that affect prolactin levels, your doctor should be aware beforehand.
During the Test
A healthcare provider will insert a small needle into a vein in your arm or hand to collect a blood sample. You may feel a slight pinch or discomfort, but it usually lasts only a few seconds. The blood is then sent to a lab for testing. The process typically takes a few minutes.
What the Results Mean
Results are interpreted by your doctor based on your overall health, symptoms, and medical history. High prolactin levels may suggest conditions like pituitary tumors, kidney problems, or certain medications affecting hormone balance. Low levels might indicate issues like thyroid problems or pregnancy. Your doctor will discuss the results with you and explain what they mean for your health.
Reference range
Adult males: 2-18 ng/mL; Females: 2-29 ng/mLN/A
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.
Clinical Significance
Short name
Prolactin Level
Frequently asked questions
What Are Common Causes of Abnormal Results?
How Often Should I Get This Test?
Can Diet or Lifestyle Affect Prolactin Levels?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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