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Test ID: A912

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Prolactin is a hormone produced in the pituitary gland and various other sites elsewhere in the body, including the brain, placenta, uterus, mammary gland, and lymphocytes of the immune system. Prolactin was named based on its function of promoting milk production (lactation), but it is now known to also have over 300 other functions in the body.

Hyperprolactinaemia (elevated prolactin) is a common cause of amenorrhoea (absence of menstruation) and is one of the most prevalent endocrine causes of female infertility. It can also lead to galactorrhea (milky nipple discharge), decreased libido, and decreased bone mass.



How to order a test


  • Lactotropin
  • “Milk Hormone”
  • Luteotropic hormone

What is Included?

Measurement of prolactin levels in a blood sample by chemiluminescent microparticle immunoassay.

Turnaround Time

1 – 3 business days
The turnaround time is not guaranteed. The average turnaround time is 1 – 3 business days from the date that the sample arrives at the laboratory. Shipping time for the sample is not included. Additional time is required if the case requires confirmatory or reflex testing, or if the sample is insufficient, or if a recollection is required.

Related Documents


Preparation Before Specimen Collection

Diurnal variations in prolactin levels occur, with higher levels in the afternoon than the morning; hence specimen collection is preferred in the morning after overnight fasting.

Specimen Type



50 μL in a microtainer


Microtainer (regular blood tube)

Collection Method

This test requires a blood sample from a finger prick. All supplies for sample collection are provided in the kit.

  1. First wash and dry hands. Warm hands aid in blood collection.
  2. Clean the finger prick site with the alcohol swab and allow to air dry.
  3. Use the provided lancet to puncture the skin in one quick, continuous and deliberate stroke.
  4. Wipe away the first drop of blood.
  5. Massage hand and finger to increase blood flow to the puncture site. Angle arm and hand downwards to facilitate blood collection on the fingertip.
  6. Drip blood into the microtainer tube.
  7. Dispose of all sharps safely and return sample to the laboratory in the provided prepaid return shipping envelope.

NOTES: Avoid squeezing or ‘milking’ the finger excessively. If more blood is required and blood flow stops, perform a second skin puncture on another finger. Do not touch the fingertip.

Specimen Storage

Maintain specimen at temperatures between 2°C and 30°C during storage and transport.

Specimen Stability

Blood samples can be refrigerated or kept at room temperature for up to 7 days.

Causes for Rejection

  • Incorrect or incomplete patient identification
  • Incorrect specimen collection
  • Inappropriate storage and transport conditions
  • Incorrect specimen volume



To measure prolactin levels in a blood sample for the diagnosis of abnormal prolactin levels, which can affect fertility, bone mass, and libido.


  • This report is not intended for use in medico-legal applications. 
  • These results should be interpreted in conjunction with other laboratory and clinical information.
  • Correct specimen collection and handling is required for optimal assay performance. 
  • Interferences from medication or endogenous substances may affect results.
  • If an elevated prolactin level is detected, it is recommended that a second blood sample is collected and analyzed before diagnosis of hyperprolactinemia.


Chemiluminescent microparticle immunoassay (Alinity i Prolactin Assay)

Reference Intervals

Adult Females: 4 – 30 ng/mL
Adult Males: 4 – 23 ng/mL

These reference ranges were obtained from“Laboratory Reference Ranges” from the Endocrine Society.