I can tell you a personal story about how dangerous too much Tylenol is. My grandmother had Parkinson's disease and would forget quite often(I don't know if this was related to the disease though) but she did. Anyway she kept taking Tylenol forgetting she would take it and kept taking it. She ended up taking about 30 of them. She went into a coma for 2 months before she died. Horrible memory of my grandmother.