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. Glutathione Depletion in Mitochondrial Diseases Glutathione Reporter Is Tylenol Safe During Pregnancy? Understanding Risk Factors Seeking Health Tylenol's Impact on Glutathione and Liver Damage Tylenol's Impact on Glutathione and Liver Damage