And this is my problem with Melatonin - it is NOT a sleep aid. It is a hormone that triggers sleep, but it will not keep you asleep once you have fallen asleep. You'll just wake up cranky. Melatonin never worked for my Trensomnia.
The only stuff that worked was Benadryl (Diphenhydramine Hydrochloride), and prescription Benzodiazepines. The stuff that REALLY worked I cannot discuss here.