The pineal gland produces melatonin, which is a hormone that plays a crucial role in regulating the sleep-wake cycle, also known as the circadian rhythm. Melatonin secretion is mainly influenced by the amount of light exposure an individual receives. In the absence of light, such as during nighttime, the pineal gland releases melatonin, which helps to make a person feel sleepy. During the day, when there is light exposure, melatonin production decreases, leading to increased wakefulness. Additionally, melatonin may have other functions, such as influencing reproductive functions and acting as an antioxidant.
