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. Let's talk Tylenol Paracetamol (acetaminophen) There are many side effects that most people don't realize. OTC does not mean it is side effect free, especially with chronic use. Even just 4 days of Acetaminophen at low doses depletes airway glutathione and alters respiratory reflex responses Smith 2013 The FASEB Journal Wiley Online Library Tylenol's Impact on Glutathione and Liver Damage Acetaminophen causes neurodevelopmental injury in susceptible babies and children: no valid rationale for controversy