I used to take Tylenol PM pretty much nightly. It was starting to lose its effectiveness and when I found myself needing a double dose to get it to keep working I stopped taking it altogether. This was about 2 months ago.

However, the reason it had lost effectiveness could also have been because I was in a manic episode a few months ago and not much would have helped.

Normally though, it did work well. Before that I took an OTC called Simply Sleep. It was amazing, but I don't know if they make it anymore or not.