Serum Prolactin (Monomeric)
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 body functions.
["Prolactin levels can help diagnose hormonal imbalances or conditions affecting the pituitary gland."]
Key facts at a glance
- LOINC
- 42607-2
- Short code
- Prolactin.monomeric SerPl-mCnc
- Synonyms
- Prolactin.monomeric 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 like infertility, irregular periods, or galactorrhea (milk production outside of pregnancy). It may also be used to evaluate symptoms such as headaches, vision problems, or unexplained weight changes that could relate to pituitary gland disorders.
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, such as smoking or certain supplements. If you’re taking medications like dopamine agonists (e.g., cabergoline), your doctor may advise timing your test around when you take them.
What Happens During the Test?
A blood sample will be drawn from a vein, usually in your arm. You may feel a slight pinch, but it’s a quick and painless procedure. The blood is then sent to a lab for analysis.
What Are Possible Results?
Results are compared to a reference range, which can vary by lab. High prolactin levels may suggest conditions like pituitary tumors, thyroid issues, or certain medications. Low levels might indicate pituitary damage or other hormonal imbalances.
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.
◆Associated findings1
Short name
Prolactin Level
Frequently asked questions
What Are Common Causes of Abnormal Results?
How Long Does It Take to Get Results?
Can Diet or Lifestyle Affect This Test?
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