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 Invigor Medical When Good Drugs Go Bad: Acetaminophen Toxicity tl;dr pharmacy Sex differences in glutathione metabolism and acetaminophen toxicity Glutathione, Tylenol & Your Health: What You Should Know Acetaminophen metabolism