oxy·​to·​cin | \ ˌäk-si-ˈtō-sᵊn How to pronounce oxytocin (audio) \

Definition of oxytocin

: a pituitary octapeptide hormone C43H66N12O12S2 that stimulates especially the contraction of uterine muscle and the secretion of milk

Examples of oxytocin in a Sentence

Recent Examples on the Web Hot weather is one potential risk factor in early deliveries because heat exposure can increase the mother’s level of oxytocin, a hormone that regulates delivery. Alan Barreca, The Conversation, "Pregnant women have a higher risk of delivering early on unseasonably hot days," 2 Dec. 2019 In addition, heat increases the levels of oxytocin, a hormone that plays a role in labor. Doyle Rice, USA TODAY, "Climate change impact: Hot temperatures shorten pregnancies, study suggests," 2 Dec. 2019 Studies in animals have shown that heat stress can increase the amount of oxytocin a mother produces. Jen Christensen, CNN, "Warming temperatures put women at risk of giving birth early, study says," 2 Dec. 2019 Another possibility is that high temperatures may trigger an increase in levels of the hormone oxytocin, which plays a role in both labor and, later, lactation. Jeffrey Kluger, Time, "How Rising Temperatures Due to Climate Change are Shortening Pregnancies," 2 Dec. 2019 Her team gave ageing mice a cocktail of oxytocin, a hormone, and ALK5 inhibitor, an enzyme. The Economist, "Uncovering how the body ages is leading to drugs to reverse it," 12 Sep. 2019 And when researchers tried to add extra oxytocin by itself, the hormone’s benefits were overwhelmed by waste accreted in old blood. The Economist, "Uncovering how the body ages is leading to drugs to reverse it," 12 Sep. 2019 The psychoactive drug boosts chemicals like serotonin and oxytocin. Will Stone, Scientific American, "MDMA, Or Ecstasy, Shows Promise As A PTSD Treatment," 21 Aug. 2019 Scientists found that in the brain’s reward system, the density of receptors for oxytocin in the prairie voles was much higher than in montane voles. Sigal Samuel, Vox, "How your brain invents morality," 8 July 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'oxytocin.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of oxytocin

1928, in the meaning defined above

History and Etymology for oxytocin

oxytoc(ic) + -in entry 1

Note: According to Science News Letter, vol. 12, no. 341 (October 22, 1927), p. 259, the name was given after pituitary extracts were "obtained in purified form from a single gland by Dr. Oliver Kamm and associates working in the research laboratories of Parke Davis and Company at Detroit."

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The first known use of oxytocin was in 1928

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Last Updated

4 Jan 2020

Cite this Entry

“Oxytocin.” The Merriam-Webster.com Dictionary, Merriam-Webster Inc., https://www.merriam-webster.com/dictionary/oxytocin. Accessed 18 January 2020.

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More Definitions for oxytocin


oxy·​to·​cin | \ -ˈtōs-ᵊn How to pronounce oxytocin (audio) \

Medical Definition of oxytocin

1 : an octapeptide hormone C43H66N12O12S2 secreted by the posterior lobe of the pituitary gland that stimulates especially the contraction of uterine muscle and the secretion of milk

called also alpha-hypophamine

2 : a synthetic version of oxytocin used especially to initiate or increase uterine contractions (as in the induction of labor) — see pitocin

More from Merriam-Webster on oxytocin

Britannica.com: Encyclopedia article about oxytocin

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experienced by way of someone else

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