What is the role of melatonin in the human body?

Melatonin plays a crucial role in regulating sleep cycles. This hormone, produced by the pineal gland in response to darkness, helps to signal the body that it is time to sleep, thereby facilitating the sleep-wake cycle. When levels of melatonin increase in the evening, it prompts feelings of sleepiness and helps to prepare the body for rest. Melatonin is also involved in the circadian rhythm, which is the body's internal clock that dictates various physiological processes over a 24-hour cycle.

This regulation of sleep is vital for overall health, influencing not just sleep quality but also various other bodily functions, including mood stabilization, cognitive function, and immune responses, all of which can be affected by disrupted sleep patterns.

Other functions, such as regulating immune functions, controlling metabolism, and promoting growth, are not directly linked to melatonin. These functions are primarily managed by other hormones and biochemical pathways in the body.