Prolactin (Serum or Plasma)
This test measures the amount of prolactin, a hormone produced by the pituitary gland, in your blood. Prolactin helps regulate breast milk production and influences other reproductive and non-reproductive functions.
["Prolactin helps control breast milk production and reproductive functions."]
Key facts at a glance
- LOINC
- 78985-9
- Short code
- Prolactin.dim SerPl-aCnc
- Synonyms
- Prolactin.dim SerPl-aCnc
- 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
This test is done to help your doctor better understand how your body is working and to look for signs of illness or conditions that may need treatment. It may be ordered to confirm a diagnosis, keep track of an ongoing health condition, or check how well a current treatment is working for you.
Your healthcare provider may order a prolactin test to investigate symptoms such as irregular menstrual periods, infertility, breast changes, or signs of hormonal imbalances. It can also be used to diagnose conditions like pituitary tumors, thyroid disorders, or certain medications that affect hormone levels.
Before your test, your care team will explain how to get ready and answer any questions you have. You may be asked to avoid certain foods, drinks, or medicines for a period of time. Be sure to tell your doctor about any allergies, medical conditions, and all medications you take, including vitamins and herbal supplements.
No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the test if it involves a blood draw. Wear comfortable clothing and let your healthcare provider know about any medications you’re taking, as some may affect results.
During the test, a trained member of your care team will walk you through each step and help you stay as comfortable as possible. The procedure is usually quick, and you can speak up at any time if you feel pain, dizziness, or any other discomfort so the staff can respond right away.
A healthcare professional will draw blood from a vein in your arm. You may feel a slight pinch, but the process is quick. The blood sample will be sent to a lab for analysis.
Your results will show whether your readings fall within a normal range or suggest a condition that needs further attention. Your doctor will review the findings with you, explain what they mean for your overall health, and discuss any follow-up tests, treatments, or lifestyle changes that may be recommended.
Results are not typically provided in absolute numbers unless specified by your provider. Instead, they are often compared to reference ranges for your age, sex, and health status. High prolactin levels may suggest conditions like tumors, thyroid issues, or certain medications, while low levels may indicate pituitary disorders.
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
High prolactin levels may indicate conditions such as pituitary adenomas, thyroid disorders (hypothyroidism), kidney disease, or the use of certain medications (e.g., antipsychotics, antidepressants). Low levels may be linked to pituitary tumors, Sheehan’s syndrome, or genetic disorders affecting hormone production.
Results are typically available within 1–3 business days, depending on lab processing times. Your healthcare provider will discuss them with you during a follow-up visit.
Most prolactin tests do not require fasting, but if instructed by your provider (e.g., for a specific type of test), avoid food or liquids for 8–12 hours before drawing blood.
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