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. Mechanistic insights into hepatic cell type specific contributions to acetaminophen induced acute liver injury Early life acetaminophen exposure, glutathione S transferase genes, and development of adolescent asthma in a high risk birth cohort Journal of Allergy and Clinical Immunology Impact of medication on protein and amino acid metabolism in the elderly: the sulfur amino acid and paracetamol case Nutrition Research Reviews Cambridge Core