Pineal Gland and Melatonin
Melatonin is the pineal gland's best-established hormonal product and is tightly linked to biological night.
Health note: This page is educational and is not a diagnosis or treatment recommendation. Supplement claims should be distinguished from established medical evidence.
A timing signal
The central circadian system regulates pineal melatonin production. Levels are normally higher at night and lower during daylight hours.
Sleep is only part of the story
Melatonin is associated with sleep timing, but reviews caution against treating it as simply a sedative or “sleep hormone.” Its role as a darkness and circadian signal is broader.
Next step
For the wider system, see our circadian rhythm guide.
Sources & further reading
NIH/PMC: Circadian Regulation of Pineal Gland Rhythmicity · PubMed: Pineal calcification systematic review · PubMed: Melatonin and the circadian system