Here's What You Should Know
Melatonin is the body's primary sleep-onset hormone, produced by the pineal gland in response to darkness detected by the retina. It does not cause sedation — it signals the biological clock that night has arrived and initiates the physiological changes associated with sleep preparation: core body temperature drop, cortisol suppression, and slowing of alertness-related neural activity. It also functions as a potent antioxidant, particularly in the mitochondria, where it reduces oxidative stress during the night's cellular repair processes.
Understanding what melatonin does — and does not do — is important for using it correctly. It is a timing hormone, not a sedative. It is most effective for circadian phase issues (jet lag, shift work, delayed sleep phase) rather than simple insomnia driven by anxiety or poor sleep hygiene. The dose that most people take is substantially higher than what the body produces naturally — which may blunt sensitivity over time.
Signs This May Be Part of Your Pattern
- Difficulty falling asleep despite feeling tired
- Circadian misalignment — naturally falling asleep late and waking late
- Frequent waking in the early morning hours (early-phase awakening)
- Disrupted sleep pattern after travel or shift work
- Waking unrefreshed despite sufficient hours in bed
- Seasonal mood and sleep changes (shorter days → less melatonin cue)
What Suppresses Natural Melatonin Production
Blue-spectrum light (from screens, LEDs) is detected by intrinsically photosensitive retinal ganglion cells and directly suppresses melatonin secretion for 2–4 hours after exposure. Late-night screen use shifts the natural melatonin rise later and later. Age significantly reduces melatonin production — people over 60 produce approximately half the melatonin of young adults, which partly explains the sleep architecture changes of aging. Alcohol disrupts sleep architecture profoundly despite initially promoting sleep onset.
How It Connects to the Bigger Pattern
Melatonin's antioxidant function operates throughout the body — it has been studied in cancer, metabolic syndrome, cardiovascular protection, and inflammatory conditions. At the mitochondrial level, it appears to be one of the primary defenses against oxidative damage during cellular repair. Its sleep-regulating role interfaces with cortisol rhythm: melatonin and cortisol are on opposing schedules — cortisol rises as melatonin falls in the morning, and falls as melatonin rises at night. Chronic stress that keeps cortisol elevated late in the evening directly suppresses melatonin onset and delays sleep.
What to Start With
For sleep onset: 0.5–1mg taken 30–60 minutes before the desired sleep time is often as effective as 5–10mg doses and less likely to cause morning grogginess or receptor blunting. For jet lag: timed appropriately to the destination time zone, not the departure zone. For general sleep support, address light exposure first (screen cutoff 1–2 hours before bed, or blue-light-blocking glasses) before escalating supplemental dose. Consistent wake time — more than bedtime — is the most powerful circadian anchor.