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
The blue light emitted from screens can interfere with your body’s production of melatonin, a hormone that helps regulate sleep.
—
Lina Begdache, The Conversation, 7 Jan. 2025
The circadian rhythm is influenced by the production of melatonin, Persaud said.
—Erica Lamberg, Fox News, 26 Dec. 2024
It’s made up of different calming essential oils like melatonin, lavender and chamomile.
—Christopher Murray, Fox News, 31 Dec. 2024
Consuming tryptophan with carbohydrates allows more to cross the blood-brain barrier, resulting in greater melatonin production.11
10.
—Amy Brownstein, Ms, Rdn, Verywell Health, 16 Dec. 2024
See all Example Sentences for melatonin 
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Lina Begdache, The Conversation, 7 Jan. 2025
The circadian rhythm is influenced by the production of melatonin, Persaud said.
—Erica Lamberg, Fox News, 26 Dec. 2024
It’s made up of different calming essential oils like melatonin, lavender and chamomile.
—Christopher Murray, Fox News, 31 Dec. 2024
Consuming tryptophan with carbohydrates allows more to cross the blood-brain barrier, resulting in greater melatonin production.11
10.
—Amy Brownstein, Ms, Rdn, Verywell Health, 16 Dec. 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 19 Jan. 2025.
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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