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. NAPQI Wikipedia Acetaminophen induces liver injury and depletes glutathione in mice brain: Prevention by Moringa oleifera extract ScienceDirect Does Acetaminophen Deplete Glutathione? Understanding the Connection Cymbiotika CYMBIOTIKA Sex differences in glutathione metabolism and acetaminophen toxicity