Neither the regular nor Ambien CR keep me asleep. My doctor has written for me to take 10 mg at bedtime, and then another when I wake up in the middle of the night. Sometimes I don't want to do that if I have to get up in just a few hours though, so I sometimes try a Xanax then. I don't know, it's all a big guessing game as far as I'm concerned! (And to think, about a year ago I was using only 2.5 mg and sleeping all night!)