The pineal gland, a pea-sized gland situated above the brain’s center, secretes the hormone melatonin (Melatonin 10mg). The regulation of your sleep and waking cycles is greatly influenced by this hormone. The hormone is often created at night, and as the sun rises in the morning, its levels decrease. Your biological clock, or circadian rhythm, and the quantity of light you receive each day impact how much melatonin you generate. There is a synthetic version of this hormone on the market that helps with jet lag symptoms and may be used to treat brief sleeplessness.