I have recently received my order of Jarrow N-Acetyl-L-Cysteine 600mg sustained release tablets. I am mainly hoping they will improve sleep and help stop the old wired, but tired kind of feeling. I know some take one tablet 3 times per day: am, afternoon and evening. The instructions on the pack say 1 tablet once or twice a day. If you use it, how often and when do you take it?