I have problems with melatonin. After a few days, it stops promoting sleep and starts interfering with sleep. Last nite was nite 3 of my taking melatonin. First 2 nights were fine. Last night, I was wide awake after 3.5 hours.
It's always like this for me.
Ya, I guess everyone's different. DH says it gives him vivid dreams and he sometimes feels a little groggy the next day. I've taken it nightly for months at a time with no undesirable effects. At least none that I'm aware of yet!