I’ve tried, really, I’ve tried. I think the longest I was able to go was just shy of a week. I got these massive headaches, was completely grouchy… I just couldn’t take it anymore. I NEEDED it. I know it’s terrible for your stomach however, and thus will try giving it up again. That being said, I did try to incorporate clear pop drinks to refrain from drinking so much of the black. Still, 2L a day of any pop can’t be good.