melatonin

noun

mel·​a·​to·​nin ˌme-lə-ˈtō-nən How to pronounce melatonin (audio)
: a vertebrate hormone that is derived from serotonin, is secreted by the pineal gland especially in response to darkness, and has been linked to the regulation of circadian rhythms

Examples of melatonin in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Fans of the Sleepy Girl Mocktail will be happy to learn that Dr. Cohen confirms it can even be layered with other sleep-promoting ingredients such as melatonin, magnesium, or valerian. Kylie Gilbert, Glamour, 19 Nov. 2024 Cherries, bananas, nuts, milk, and whole grains contain sleep-promoting nutrients like melatonin, tryptophan, potassium, and magnesium, which are also ideal for nighttime snacking.3 1. Jillian Kubala, Health, 4 Nov. 2024 In 2022, Yo-El Ju, a neurologist and sleep medicine specialist at Washington University in St. Louis, shared five foods that are naturally rich in melatonin: Nuts, especially walnuts Fish, particularly salmon Eggs Tart cherries Cow’s milk 2. Renée Onque, CNBC, 2 Nov. 2024 But what is the best time to take a melatonin supplement for a good rest? Michael Franco, New Atlas, 4 Nov. 2024 See all Example Sentences for melatonin 

Word History

Etymology

mela-, extracted from Greek melan-, mélās "black, dark" + -tonin (in serotonin); so named because the hormone can lighten skin color in animals by reversing the effect of melanocyte-stimulating hormones — more at melano-

Note: The word was probably introduced in the first published description of the hormone's isolation: Aaron B. Lerner, et al., "Isolation of melatonin, the pineal gland factor that lightens melanocytes," Journal of the American Chemical Society, vol. 80, no. 10 (May 20, 1958), p. 2587.

First Known Use

1958, in the meaning defined above

Time Traveler
The first known use of melatonin was in 1958

Dictionary Entries Near melatonin

Cite this Entry

“Melatonin.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/melatonin. Accessed 30 Nov. 2024.

Kids Definition

melatonin

noun
mel·​a·​to·​nin ˌmel-ə-ˈtō-nən How to pronounce melatonin (audio)
: a hormone that is secreted by the pineal gland especially in response to darkness and has been linked to the regulation of bodily functions or activities (as sleep) that occur in approximately 24 hour cycles

Medical Definition

melatonin

noun
mel·​a·​to·​nin ˌmel-ə-ˈtō-nən How to pronounce melatonin (audio)
: a vertebrate hormone C13H16N2O2 that is derived from serotonin, is secreted by the pineal gland especially in response to darkness, and has been linked to the regulation of circadian rhythms

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