pro·​lac·​tin prō-ˈlak-tən How to pronounce prolactin (audio)
: a protein hormone of the anterior lobe of the pituitary that induces lactation

Examples of prolactin in a Sentence

Recent Examples on the Web While evidence is mixed, it is believed that milk thistle may stimulate prolactin, the hormone needed to make breast milk.2 Note that Legendairy Milk is fenugreek-free. Lainey Younkin, Ms, Rd, Parents, 15 May 2024 One way dopamine assists with expanding T levels is by stifling prolactin. Amber Smith, Discover Magazine, 6 Jan. 2024 The hormone that stimulates pigeon milk production is called prolactin, which is the same hormone that causes lactation in mammals like us! Popsci Staff, Popular Science, 28 Feb. 2024 For a short time, your pelvic muscles contract, your consciousness changes, and the blood levels of two hormones (oxytocin and prolactin), which promote social bonding, increase. Yuliya Klochan, Health, 20 Oct. 2023 Excess prolactin, a hormone that causes breast growth during puberty and produces breast milk, might throw off your menstrual cycle. Jessica Migala, Health, 11 Sep. 2023 The most important next step is to discover where the prolactin is coming from. Dr. Keith Roach, oregonlive, 1 Aug. 2023 In men, high levels of prolactin commonly cause erectile dysfunction and low libido. Dr. Keith Roach, oregonlive, 1 Aug. 2023 Research has shown that THC, the active compound in cannabis, can inhibit the release of prolactin, a hormone responsible for milk production. Amber Smith, Discover Magazine, 31 July 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'prolactin.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


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

First Known Use

1932, in the meaning defined above

Time Traveler
The first known use of prolactin was in 1932

Dictionary Entries Near prolactin

Cite this Entry

“Prolactin.” Dictionary, Merriam-Webster, Accessed 18 Jun. 2024.

Medical Definition


pro·​lac·​tin prō-ˈlak-tən How to pronounce prolactin (audio)
: 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

More from Merriam-Webster on prolactin

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