Melatonin is a hormone produced inside the body that tells the body when it is bedtime.

People have a genetic sleep code called their chronotype, which dictates when their brain releases hormones like melatonin, cortisol, adrenaline, and dopamine.

Nightly melatonin production actually begins in the morning.

Staying in sync with daylight by going to bed earlier and waking up closer to sunrise helps the brain regulate hormones like melatonin for sleep and cortisol for waking up.