# Melatonin

Melatonin is a hormone secreted by your pineal gland in response to darkness. It signals biological night and helps align your circadian system. It helps you fall asleep, modulates your core body temperature, and has antioxidant effects. Your own melatonin declines with age, and bright evening light suppresses its release. Low-dose melatonin taken as a supplement is used to address jet lag, shift work, and delayed sleep-phase patterns.

## Sources

- Lewy AJ, Wehr TA, Goodwin FK et al.. (1980). Light suppresses melatonin secretion in humans. Science. https://doi.org/10.1126/science.7434030
- Zisapel N. (2018). New perspectives on the role of melatonin in human sleep, circadian rhythms and their regulation. British Journal of Pharmacology. https://doi.org/10.1111/bph.14116

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_Canonical: https://longevity-switzerland.com/en/glossary/melatonin · Part of Longevity Cities · Updated 2026-06-22_