darn, dude, that's a lot of melatonin. haha. Yeah it messes with your circadian rhythm. If you just use it to "correct" your sleeping problem for a few nights, then stop, I think it's effective. 
This. It's not meant as a sleeping pill. It'll work that way initially if you're sleep is out of whack though, generally. As stated, it's meant to reset your circadian rhythm which helps with the cycles of day and night.
Years ago, I went to my doctor for some help with falling asleep. I told him my mind raced, and I had issues falling asleep. He prescribed, off label, Seroquel, an anti-psychotic. Basically, you take it, and in 45 minutes, you get extremely groggy and off to dream land you go. One of the coolest feelings. But after my one bottle, I didn't really use it after.
My sleep was having issues again a little more recently, and took melatonin. I started with 5mg, and it sort of helped. I found that 10mg was closer to what my body needed.
And for the record, studies have shown that backlight, from monitors, phones etc... affects your melatonin levels. If you use devices a lot, you'll need more to compensate.
Edit - went to find an article that showcased it for anyone interested (I read about it awhile ago) :
http://www.dailymail.co.uk/sciencetech/article-2194806/Using-mobile-phones-tablets-bed-affecting-sleep-warn-scientists.htmlThis is a reason why F.lux wouldn't be a bad idea for some people.
