I thought I would pop in to mention my experience with melatonin, just to offer yet another perspective. I am part of the same group that Tincup mentions, run by a guy who advocates for high dose melatonin and often refers to various research articles touting its benefits. I worked my way up through progressively larger doses, from just a few mg each night, to now taking around 250mg/night. I use a bulk melatonin powder (no fillers) which I place under my tongue for a few minutes before washing down with some water and my other nighttime pills. I have had almost no side effects from any of the melatonin doses I've taken (except daytime sleepiness for the first couple of weeks), though I know some do have them. The benefits I attribute to the melatonin is a much strong circadian rhythm (I also use red-light therapy in the AM in an effort to strengthen my circadian rhythm) and just a bit more "pep in my step" during the day. This last one surprised me. I thought I would be sleepy all the time (and for the first week or two, I was), but once I started supplementing with higher doses of melatonin the grogginess went away and I felt so much more energy during the day.