I have experience with every sleep-inducing drug imaginable, and after much trial-and-error, have concluded that Ambien works the best for me, with Lorazepam a close second.

The thing to remember about Ambien, in addition to everything else mentioned here, is that you want to take it on an empty stomach, otherwise, it will take forever to work, or not at all. My solution is to wait until just before dinner - as in, they've put the food in front of me, and take the Ambien with a glass of wine. Having it go down first allows it a few minutes to dissolve. Then I eat, and I'm usually almost gone by the time the tray is removed. Nice FA's take my tray away and stow the tray table for me, while leaving a bottle of H2O in the seat pocket.

At home, Ambien allows me to sleep almost all night - on a plane, usually about 4 hours. But it's still in my system, so certainly memory loss can be a bit of a problem if I have to function during the NEXT four hours.

I found the post about Lorazepam intriguing. I take it as an anti-anxiety med regularly, and I sleep like a baby on it. However, it works differently - it doesn't knock me out the way the Ambien does, but it allows me to sleep longer and better. If the doctor deems it safe, perhaps a combination of both? Sort of a one-two punch, if you're determined to get that 8 hours.

As far as docs prescribing it - I go to the most conservative doc you can imagine, and I tell her up front what it's for - two or four or whatever long-haul flights, and she gives me just enough to cover it and not a pill more. Perhaps a few extra to counter jet lag. Ambien's great for that - changing your body clock.

One final thought - once you get used to Ambien's effect, it can be "fun" to take it a little early and spend some time in goofy-land. I don't actually do anything during that time - I just sit there enjoying the sensation. But it can become addictive, so be disciplined about using it. And be VERY CAREFUL about alcohol use. One glass of wine speeds things up, but more than that and you'll likely pour it all over yourself as you fall asleep. Very attractive.

Hope this helps.