Research

Hormonal

Melatonin regulates circadian rhythms and sleep-wake cycles by acting on the suprachiasmatic nucleus (SCN) and pineal gland, with secretion peaking at night.

Melatonin is your body's natural signal for darkness and sleep. It is produced by the pineal gland in response to darkness, peaks at night, and helps regulate your sleep-wake cycle. Exposure to light at night suppresses this natural production.

StrongSupportsVERY_HIGH confidence
One of the earliest known functions of melatonin is its impact on circadian rhythms’ regulation. Light is the environmental factor known to affect melatonin secretion. Melatonin acts directly on the SCN and modulates clock function.
Bahare Salehi et al. · Cells · 2019

Why this rating

This is a foundational, widely accepted physiological fact cited extensively in the review.

Source

Melatonin in Medicinal and Food Plants: Occurrence, Bioavailability, and Health Potential for Humans

Bahare Salehi et al. · Cells · 2019

DOI 10.3390/cells8070681

narrative_reviewCited 172×
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DOI resolved against Crossref · corpus check 2026-06-10

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