If you’re wondering whether you should take the hormone melatonin for a sleep disorder, bear in mind that melatonin is synthesized from the neurotransmitter serotonin (as described in this paper published in the journal Cell & Tissue Research). The functional approach avoids taking melatonin (except temporarily for extensive time zone travel) because of the possibility of suppressing native hormone pathways. This is only one of a number of factors that can cause or contribute to insomnia, but the possible need for physiological support with precursors and co-factors to normalize serotonin production and conversion to melatonin shouldn’t be overlooked since they can be depleted by stress.