GABA works best for me on an empty stomache. I dont think it's as potent for me as Phenibut. But more potent isnt always what u want either.
For sleep, I think there's a little window about 20 minutes after dosing where i need to make sure conditions are right for sleep. If I miss that window, i still feel relaxed from gaba, but it wont help me fall asleep after that point. This could possibly be one reason why maybe it works for u 1 time, and then the next time it doesnt.
I've always just used bulk powder. I'm pretty sure it's odorless and tasteless like Taurine... correct me if I'm wrong