melatonin
noun
mel·a·to·nin
ˌme-lə-ˈtō-nən 
: 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
But what is the best time to take a melatonin supplement for a good rest?
—
Michael Franco, New Atlas, 4 Nov. 2024
These moms produced far less melatonin, a hormone that helps regulate their cycles of sleep and wakefulness, and this may have helped delay the timing of births.
—Brian Handwerk, Smithsonian Magazine, 25 Oct. 2024
This supplement contains only melatonin as an active ingredient.
—Melissa Nieves, Health, 13 Sep. 2024
That, says Cai, is because the release of the sleep hormone melatonin changes, occurring later in the evening.
—Jeffrey Kluger, TIME, 4 Sep. 2024
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Michael Franco, New Atlas, 4 Nov. 2024
These moms produced far less melatonin, a hormone that helps regulate their cycles of sleep and wakefulness, and this may have helped delay the timing of births.
—Brian Handwerk, Smithsonian Magazine, 25 Oct. 2024
This supplement contains only melatonin as an active ingredient.
—Melissa Nieves, Health, 13 Sep. 2024
That, says Cai, is because the release of the sleep hormone melatonin changes, occurring later in the evening.
—Jeffrey Kluger, TIME, 4 Sep. 2024
See all Example Sentences for melatonin
Dictionary Entries Near melatonin
Cite this Entry
“Melatonin.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/melatonin. Accessed 22 Nov. 2024.
Copy CitationKids Definition
melatonin
noun
mel·a·to·nin
ˌmel-ə-ˈtō-nən
: 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
: 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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