Reaching for Tylenol when baby is fussy? Here's some information worth knowing. A baby's liver isn't fully mature until around 2 years old Meaning their ability to process certain substances is still Acetaminophen Toxicity Toxicology UWorld Medical Library Tylenol, Autism, And The Glutathione Connection OC Integrative Medicine Acetaminophen Pathway (toxic doses), Pharmacokinetics Is Tylenol Safe During Pregnancy? Understanding Risk Factors Seeking Health 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.