Melatonin

You can thank the pineal gland for most of your melatonin, though other tissues, including the intestines and the retina, are also capable of producing it.

Melatonin is the sleep hormone; it functions primarily in helping you fall asleep at night; sleep well, soundly and deeply; and wake up in the morning. It is what makes you yawn and want to go to bed at night, and (by activating thyroid hormones) it's what prompts you to arise - if you have the luxury of not handing that job over to an alarm clock. Melatonin creates your body's day/night rhythm, including the timing with which other hormones are released. It is helpful with sleep problems, including those from shift work and jet lag.

Without enough melatonin, you'll get poor, superficial sleep deprived of dreams and full of agitation and brooding. You'll be quite the night owl, because your body won't know when to go to bed. You'll have a hard time getting to sleep and going back to sleep when you wake up during the night. You'll feel tired when waking up and will never feel well rested, so you'll often be in a bad mood. You'll be hard hit by jet lag.

If you don't have sufficient melatonin, you'll often feel tense, anxious, irritable, and aggressive. You'll look older than your age, thanks in part to prematurely graying hair and bags under your eyes. No one looks his best when not well rested, and few of us hide it very well.

Researchers have discovered that the pineal gland is the body's "time clock" and regulates the body's rate of aging. Melatonin given to 18 month-old mice (the human equivalent of 60 years) has been shown to dramatically reverse aging, extending their life to the human equivalent of 105 years. (ref: Pierpaoli et el The Melatonin Miracle 1995).

Like many other hormones, melatonin levels decrease with age. This can lead to a reduced immune system and increased exposure to disease like cancer, heart disease and high blood pressure.