It looks like 1/8th of the atoms in the molecule are sulphur, if I read this correct:
https://en.m.wikipedia.org/wiki/Acetylcysteine
yeah i,m not sure how much it woudl take to cause health issues,- i do know some folks are really allergic to sulfur though-
Is the sulpher in the NAC of the same type as sulpheraphane. That is, do they do the same thing. Such that if you take NAC you don’t need to take sulpheraphane?