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: If youve felt a sense of confusion this week over the White Houses announcement on Tylenol and autism, as well as some of the unproven medical advice given during that press conference, I highly Acetaminophen's effects on vaccines Vital Record