I kind of accidently bumped into this. It's suposed to work like NAC in raising GSH, but it's a lot stronger. (at least this is what the producers claim.....) It's for sale on this website http://www.cellgevity4life.com/cellgevity.html (at a high cost.) Has anyone ever tried one of these products? Or ever heard of it? I found one positive testimonial one the internet http://brianmarsh.com/health/36-symptoms-of-my-chronic-fatigue-syndrome/ "D-ribose-l-cysteine" doesn't yield a lot of results on pubmed, altough it's used to raise GSH (succesfully) in animal studies.