Zolpidem
"My whole life I've had trouble getting to sleep so I"m always not fully rested and would sleep in late every day.  I took 5mg under the tongue at first that works great - within 45 mins I'm relaxed enough to sleep.  Now, however I've had to take 10mg after a year of taking 5 doesn't put me to sleep.  Never done anything weird on Ambien unless I had a beer before taking it.  Unfortunately I've used 2.5mg occasionally just to rest 2-3 hours before bed.  Doesn't seem to have any negative effects but may be addictive.  Haven't tried a night without it since a year ago."