What is the role of melatonin in sleep?

Short Answer

Melatonin is a hormone that signals darkness and helps shift your circadian clock toward sleep. It’s more of a timing cue than a sedative, and it works best when taken at the right time.

Why This Matters

This matters because many sleep issues are circadian issues: your body wants sleep later or earlier than your schedule. Melatonin can shift timing, which leads to easier sleep onset when used strategically (often with morning light). Mis-timed use results in grogginess or minimal benefit, and it can mask problems like apnea or poor sleep hygiene.

Where This Changes

It’s most useful for jet lag, delayed sleep phase, shift work adjustments, and older adults with lower endogenous melatonin. Dosing and timing matter, and if you’re pregnant, on multiple medications, or have complex health conditions, it’s wise to discuss supplementation with a clinician.