Update Writer #1, 2011-07-06 It seems like longer, but I’ve been caffeine free for 8 days now. I’ve been having good days and then days with headaches. I’ve felt even sustained energy from my natural body chemistry without caffeine influence. With that said, I do notice that I get sleepy when sitting around. Alternatively, coffee keeps your eyes bugged out during down times. This is a major difference. Random Awesomeness caffeinecoffeehealth