Circadian Rhythm: A Practical Beginner's Guide
Your circadian system organizes roughly 24-hour patterns across sleep, hormones and other physiology. The pineal gland participates by producing melatonin rhythmically.
Health note: This page is educational and is not a diagnosis or treatment recommendation. Supplement claims should be distinguished from established medical evidence.
The central clock
In mammals, the suprachiasmatic nucleus (SCN) is a central circadian pacemaker. Pineal melatonin is under circadian control and communicates biological-night timing.
Light matters
Light exposure can suppress melatonin and shift circadian timing. This is why the timing of light—not just supplements—belongs in any serious discussion of sleep and circadian health.
Related guides
Continue with pineal gland and melatonin or pineal gland basics.
Sources & further reading
NIH/PMC: Circadian Regulation of Pineal Gland Rhythmicity · PubMed: Pineal calcification systematic review · PubMed: Melatonin and the circadian system