amscray,
NAC really does work. Somehow it neutralizes APAP but you must take it with your meds.
I used to get pains around lower right quadrant (liver) whenever I took over 3000mg APAP. Since I've added NAC. NO more pains!!!! For further infoCheck out that link above. That should answer all your questions. I found a good source for it www.vitacost.com 90 500mg. caps for $12.00. The stuff smells terrible but it works.
Good luck
GregR