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
Example Sentences
Recent Examples on the Web It's buy one, get one 50 percent off on everything from contact solution and thermometers to nose drops and melatonin gummies. 
Lydia Mansel, Peoplemag, 16 Aug. 2022 The components of these melatonin gummies are quite basic. The Salt Lake Tribune, 25 May 2022 Can melatonin gummies solve family bedtime struggles? Los Angeles Times, 24 Mar. 2022 Weighted blankets have been shown to increase melatonin and serotonin production while decreasing cortisol levels to help the body relax and experience better sleep. Olivia O'bryon, Forbes, 4 Aug. 2022 Melatonin levels start to rise three hours before bed, and the metabolic process following food intake is negatively influenced when the melatonin levels rise. Alina Dizik, WSJ, 13 Aug. 2022 Our core body temperature, which correlates to the body clock, decreases before bed as sleep-promoting melatonin levels rise. Alexa Mikhail, Fortune, 24 July 2022 Don’t sleep on what kids may be doing with your melatonin supplements. Bruce Y. Lee, Forbes, 7 June 2022 Due to the boost in popularity, the medical industry spent $826 million on melatonin supplements in 2020, a 43% increase from the year before, said Dr. Michael Daignault, an emergency physician. Gabriela Miranda, USA TODAY, 3 Feb. 2022 See More
Lydia Mansel, Peoplemag, 16 Aug. 2022 The components of these melatonin gummies are quite basic. The Salt Lake Tribune, 25 May 2022 Can melatonin gummies solve family bedtime struggles? Los Angeles Times, 24 Mar. 2022 Weighted blankets have been shown to increase melatonin and serotonin production while decreasing cortisol levels to help the body relax and experience better sleep. Olivia O'bryon, Forbes, 4 Aug. 2022 Melatonin levels start to rise three hours before bed, and the metabolic process following food intake is negatively influenced when the melatonin levels rise. Alina Dizik, WSJ, 13 Aug. 2022 Our core body temperature, which correlates to the body clock, decreases before bed as sleep-promoting melatonin levels rise. Alexa Mikhail, Fortune, 24 July 2022 Don’t sleep on what kids may be doing with your melatonin supplements. Bruce Y. Lee, Forbes, 7 June 2022 Due to the boost in popularity, the medical industry spent $826 million on melatonin supplements in 2020, a 43% increase from the year before, said Dr. Michael Daignault, an emergency physician. Gabriela Miranda, USA TODAY, 3 Feb. 2022 See More 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
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