"ever since i started using this, (thanks so much, doc!) i have been in heaven. i have had problems sleeping for months, maybe even a year but not as extreme then. i start to feel tired and my eyes start to want to shut just 20-25 mins after i take this! the &quot;window of opportunity&quot; where it is most obvious it&#039;s working (when i feel sleepiest) is (obviously) the time i go to bed. the one time i missed that window was out of experimentation, as i wanted to know if it would knock me out as i was sitting on my couch. didn&#039;t work! when i went to bed that night it was very hard to do so. so now, i always head straight to bed when i feel sleepiest."