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 uses up the liver's stores of GLUTATHIONE. Glutathione is the body's most important ANTIOXIDANT. Old and New Analgesic Acetaminophen: Pharmacological Mechanisms Compared with Non Steroidal Anti Inflammatory Drugs Acetaminophen metabolism Can paracetamol (acetaminophen) be administered to patients with liver impairment? Hayward 2016 British Journal of Clinical Pharmacology Wiley Online Library