Melatonin is a hormone produced by the body that helps regulate sleep; melatonin levels typically increase during hours of darkness and decrease with exposure to daylight.
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definition
Basic physiological role of melatonin in sleep-wake regulation.
Melatonin supplements are widely available for over-the-counter purchase in the United States, while melatonin is available only by prescription in some other countries.
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availability
Regulatory availability of melatonin differs between the U.S. and other countries.
Cognitive behavioral therapy is considered a more effective treatment for chronic insomnia than relying on supplements such as melatonin.
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medical
Treatment guidance for chronic insomnia prioritizing behavioral therapy over supplements.
Tryptophan is an amino acid precursor to melatonin, and increased brain uptake or availability of tryptophan can promote melatonin production, which helps regulate sleep.
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temporal
Biochemical pathway linking dietary tryptophan to the sleep-regulating hormone melatonin.