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 Myth busting, Acetaminophen version. "Avoid Acetaminophen (Tylenol) because it causes glutathione depletion". Truth?? As a pediatrician and ER doctor and as moms we're often asked about this. And we understand why: g glutamyl cycle. Depletion of glutathione by acetaminophen leads to Download Scientific Diagram What can I give my 2 year old to support his liver after having to unfortunately give Tylenol? Acetaminophen Toxicity: How Genetic Susceptibility Combines with Environmental Factors