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Prolactin

Published: July 27, 2026Updated: August 25, 2026

Prolactin is a hormone produced by the pituitary gland that plays a crucial role in reproductive health, particularly in lactation and fertility.

Quick summary

Prolactin is essential for lactation and fertility and its levels can indicate various reproductive disorders.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 25, 2026Editorial policy

Key facts at a glance

Units
ng/mL
Clinical utility
diagnostic
Result kind
quantitative
FDA-cleared
Roche Prolactin, Abbott Prolactin, Siemens Prolactin
interpretation: {"text":"Levels above 23 ng/mL may indicate prolactinoma, hypothyroidism, or PCOS.","label":"High Prolactin"}; {"text":"Levels below 4 ng/mL may suggest pituitary disorders or the use of certain medications.","label":"Low Prolactin"}

Prolactin is a hormone primarily produced by the anterior pituitary gland. Its main function is to stimulate milk production in women after childbirth, but it also plays a role in regulating fertility and the immune system.

Normal prolactin levels in non-pregnant individuals range from 4 to 23 ng/mL. Elevated levels can indicate conditions such as prolactinoma, hypothyroidism, or polycystic ovary syndrome (PCOS).

Low levels of prolactin are less common but can be associated with pituitary disorders or the use of certain medications. Testing prolactin levels is crucial for diagnosing reproductive and endocrine disorders.

Frequently asked questions

What are the symptoms of high prolactin levels?
Symptoms can include irregular periods, infertility, and galactorrhea (unexpected milk production) in women, and erectile dysfunction and decreased libido in men.
How is a prolactin test performed?
A blood sample is taken, usually in the morning when prolactin levels are highest, and analyzed in a laboratory.
  1. 1
    Prolactin - Lab Tests OnlineSource
  2. 2
    Mayo Clinic - Prolactin TestSource

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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

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 25, 2026. · Read our editorial policy