I actually sleep a lot better since trying one supplement. But read on and find out (this is slightly edited from the original post here):
For me (focusing on ingredients, rather than specific brands here), this is what works and what doesn't:
Doesn't help me sleep any better, but it does give me more vivid dreams. Extremely vivid dreams, actually. When I was using this, I often found it took an hour or two after waking up before I could figure out that my dreams last night never really happened. However, that is at a 2 - 3 mg dose. At a 1 mg dose I don't notice much difference. The only reason I still take it is because it's part of Alacer's CMA (the name was recently changed to "Emergen-C Sleep Aid", probably for branding reasons and likely because the name CMA was too close to ZMA) formulation, and I otherwise love Alacer's products.
Awful stuff. I wake up groggy, unable to think. Clouds my brain like you wouldn't believe. I don't drink, but if I had to hazard a guess, when I take even small doses of this stuff, I figure this is what a major hangover would feel like.
Makes me unable to sleep, since it gives me a killer headache.
Decent. I sleep *a little* better. Whereas I usually wake up 10 times a night, with this I might only wake up 7 or 8 times a night. Not much, but I'll take what I can get. I haven't noticed any mood-enhancing or appetite suppressing effects, despite claims on the labels of several products.
The best stuff - in powder form. In pill form, this does nothing for me. In powder form, a 6-7 gram dose does wonders. (It's also sometimes billed as a Growth Hormone enhancer - but I have noticed no Growth Hormone enhancing or fat loss effects).
The one drawback to GABA is the side effect of shortness of breath and tingling of the skin. When I first tried this in powder form, it freaked me out - I was sure I was going to faint. Now that I expect it, it has actually become a signal for the best time for me to be in bed, trying to fall asleep. When the shortness of breath kicks in, if I stay up too much longer, I won't fall asleep as easily.
A lot of the other herbal supplements (Passionflower, Hops, Chamomile, etc.) have been useless for me.