Linked from
The 38 pages that link to Melatonin, each with the reason it gives.
SerotoninCompared with: Its role in sleep is distinct from serotonin’s broader signaling functions.
CaffeineCompared with: Its sleep-timing effects contrast with caffeine’s tendency to delay sleep.
TemazepamCompared with: Its role in sleep timing differs from temazepam's direct sedative action.
FlunitrazepamCompared with: It represents a non-sedative alternative for some sleep-timing problems.