Serum Prolactin Level (Mass Concentration)
This test measures the amount of prolactin, a hormone produced by the pituitary gland, in your blood. Prolactin helps regulate milk production and influences other bodily functions.
["Prolactin levels can help diagnose hormonal imbalances or conditions affecting the pituitary gland."]
Key facts at a glance
- LOINC
- 55502-9
- Short code
- Prolactin 20M pTRH IV SerPl-mCnc
- Synonyms
- Prolactin 20M pTRH IV SerPl-mCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 0.8
- Ref high
- 1.2
- Critical range
- — – 5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85610
- SNOMED
- 396252006
- 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 (high prolactin levels), which can cause issues like infertility, irregular menstrual cycles, or symptoms of low thyroid function. It may also be used to evaluate symptoms such as headaches, vision changes, or unexplained galactorrhea (milk production outside of pregnancy).
What to Expect Before the Test
No special preparation is usually needed, but you may be asked to avoid certain medications that can affect prolactin levels, such as certain antidepressants or antipsychotics. If you’re taking these, let your provider know before the test.
During the Test
A blood sample will be taken from a vein, typically in your arm. You may feel a slight pinch, but it usually doesn’t cause significant discomfort. The sample is then sent to a lab for analysis.
What the Results Mean
Results are compared to a general reference range, but individual ranges can vary. High prolactin levels may suggest pituitary tumors or other conditions affecting hormone regulation, while low levels could indicate thyroid issues or other health concerns.
Reference range
INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A
Inform your healthcare provider if you are taking blood thinners. No special preparation required.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated prolactin levels can interfere with normal hormone function, potentially leading to fertility problems, menstrual irregularities, or symptoms like breast tenderness. Low prolactin levels may signal thyroid dysfunction or other hormonal imbalances. Always discuss results with your healthcare provider for personalized interpretation.
Short name
Prolactin
Frequently asked questions
How long does it take to get the results?
Can I eat or drink before this test?
Does this test require fasting?
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