How does the chemical melatonin help regulate our sleep cycle?

Melatonin is a hormone produced by the pineal gland in response to darkness, signaling to the body that it is time to sleep. It helps regulate the sleep-wake cycle, or circadian rhythm, by promoting feelings of drowsiness and lowering body temperature. As melatonin levels rise in the evening and fall in the morning, it helps synchronize the body's internal clock, enhancing sleep quality and duration. Disruptions in melatonin production can lead to sleep disorders or difficulties in maintaining a regular sleep pattern.