Mirtazapine
"Taking 30mg daily now for insomnia.  Best medicine  I have ever taken for insomnia.  When I took my first 30mg pill it worked great.  Maybe too good.  I slept 8 hours and if I didn't have any repsonsibilities it felt like I could sleep another 4 hours.  I had to drag myself out of bed, but it still was a quality sleep.  I started taking as needed but at lower does.  3.4mg, 7.5mg, 15mg.  Seems to have a long half-life so some days I didn't take at all and it still worked.  After awhile the effects started wearing off so I started taking 30mg every day for about a month now and it seems to be still working.  I tried to increase to 45mg but at that dose it seems not work for sleep anymore.  The maximum I can take for sleep is 30mg."