prolactin

noun

pro·​lac·​tin prō-ˈlak-tən 

: a protein hormone of the anterior lobe of the pituitary that induces lactation

Examples of prolactin in a Sentence

Recent Examples on the Web

Non-breeding mole-rat females are known to run high on prolactin, a hormone that also suppresses fertility during lactation in nursing mammals. — Jacek Krywko, ArsTechnica, 21 July 2026

Elevated levels of prolactin can suppress testosterone production and may indicate an underlying pituitary disorder. — Melissa Rudy, FOXNews.com, 20 July 2026

Breastfeeding, which can cause prolactin and oxytocin levels to soar, also complicates the issue. — Theara Coleman, TheWeek, 13 July 2026

In new mothers, for instance, an increase in the hormone prolactin helps lay the groundwork for breastfeeding. — Joshua Rothman, New Yorker, 19 June 2026

Word History

Etymology

pro- entry 2 + lact- + -in entry 1

First Known Use

1932, in the meaning defined above

Rhymes for prolactin

• actin

Medical Definition

prolactin

noun

pro·​lac·​tin prō-ˈlak-tən 

: a protein hormone of the adenohypophysis of the pituitary gland that induces and maintains lactation in the postpartum mammalian female

—abbreviation PRL

called also luteotropic hormone, luteotropin, mammotropin