Among the various hormonal supplements that have become popular over the
last few years, melatonin has been the first, propelled by the book on the
Melatonin Miracle by the Italian researcher Walter Pierpaoli.
Melatonin is a hormone secreted by the pineal gland, and among other
things, it is largely responsible for regulating wake / sleep cycles.
Melatonin supplements will often improve sleep in patients who have a hard
time falling asleep or sleeping for a sufficient number of hours.
However, melatonin became so popular not because of its effect on sleep but
because experiments with laboratory animals have shown that melatonin seems
to substantially increase life span.