"this drug is scary!!! the 20mg dose puts me on the threshold of sleep, without allowing me to actually fall asleep. i accidentally thought the maximum dose was 40mg so i took two 20mg pills. it really did make me fall asleep, but you can forget about trying to function at all the following day. i am quite desperate for sleep, so now i take 35mg when i have absolutely nothing going on the next day. i am retired and can stay at home without having to drive anywhere. the half-life of this drug is 12 hours!!! that means if you take a 20mg pill, your still going to have 10mg in your system 12 hours later. i can see why people fall asleep driving to work. ambien on the other hand has a half-life of only of about 2.5 hours. dangerous drug!!!"