Here’s a starting point:

https://pmc.ncbi.nlm.nih.gov/articles/PMC5241507/#B1

TLDR: NAC is a derivative of an amino acid called cysteine, as such it is a precursor for one of the most important antioxidants in the body and it can modulate key metabolic pathways associated with good health across a variety of organs, notably for decades it has been a universally successful antidote for acetaminophen (Tylenol) overdose, it’s available over the counter but NAC is not naturally found in foods, eating cysteine-rich foods like chicken turkey yogurt etc is the next best bet.