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. Full article: The development and hepatotoxicity of acetaminophen: reviewing over a century of progress Electrochemical evidences in oxidation of acetaminophen in the presence of glutathione and N acetylcysteine Chemical Communications (RSC Publishing) PDF] Evidence that Increased Acetaminophen use in Genetically Vulnerable Children Appears to be a Major Cause of the Epidemics of Autism, Attention Deficit with Hyperactivity, and Asthma Semantic Scholar Tylenol And Glutathione Invigor Medical Acetaminophen's Role in Autism and ADHD: A Mitochondrial Perspective