Yes, that's a stable precursor of L-Cysteine, required if you want to powder and pill as a supplement. Once in the body, it is converted to Cysteine, then glutamine(edit: wrong one, it's glutathione), etc.. It's no different than using a Creatine powder, like creatine monohydrate. That is a stable form of Creatine. Once in the body, it is processed to Creatine phosphate, then adenosine, donating a phosphate to ABP creating ATP etc. Or something to that effect, I forget the full pathway. Good for high energy muscle use like lifting heavy and sprinting. Lets remember that GNC and the supplement manufacturers make a shitload of money too.