Hi, Daniele, I am not sure what the question is . . . are you asking to compare the usefulness of NAC versus GSH? They are both useful, but GSH gives you everything that NAC gives you (GSH is a cysteine donor, too!) and more (GSH participates in all sorts of redox activities throughout the body, which cysteine does not). We use both, but if I had to choose one, I would choose GSH. NAC in too-high doses is toxic; GSH is non-toxic.