This is very brief because I don't remember all of it....Acetaminophen is metabolized by the P450 system in the Liver and one of the products is the toxic metabolite NAPQI. Glutathione (GSH) is normally present to convert NAPQI to a non-toxic compound, however, if there is an overdose NAPQI accumulates because there isn't enough of GSH around and results in liver damage. The antidote is n-acetylcysteine which helps bind to toxic compounds like NAPQI BUT also helps in regenerating and gathering the body's stores of GSH.....hope it helps some.