Yes there is good evidence that acetaminophen (the active ingredient in Tylenol) can deplete glutathione under certain conditions. But whether that matters depends on dose, duration, and individual factors. Tylenol and Glutathione: A Closer Look At Their Relationship Tylenol and Glutathione: A Closer Look At Their Relationship View of Acetaminophen, the missing anion gap in the patient with metabolic acidosis The Southwest journal of medicine Acetaminophen causes neurodevelopmental injury in susceptible babies and children: no valid rationale for controversy