Active LitigationLast updated: February 20, 2026
Acetaminophen — sold under the brand name Tylenol by Kenvue (formerly Johnson & Johnson) and as dozens of store-brand generics by Walmart, CVS, Walgreens, Target, Costco, Meijer, and others — was the most commonly used pain reliever during pregnancy in the United States for decades. Starting with a landmark 2018 American Journal of Epidemiology meta-analysis of 130,000 mother-child pairs, and culminating in a 2021 consensus statement signed by 91 scientists published in Nature Reviews Endocrinology, accumulating evidence linked prolonged prenatal acetaminophen exposure to significantly elevated risks of autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD). The federal multidistrict litigation, MDL-3043 (In re Acetaminophen — ASD/ADHD Products Liability Litigation) in the Southern District of New York, was dismissed in August 2024 after Judge Denise L. Cote excluded all plaintiffs' general causation experts under the Daubert standard. Critically, the Second Circuit Court of Appeals heard oral arguments on November 17, 2025 — and two of the three judges on the panel openly questioned whether Judge Cote acted too aggressively in excluding the expert testimony. A reversal by the Second Circuit could reinstate thousands of federal cases. Separately, California state courts (Alameda County) and Illinois state courts (St. Clair, Madison, and Cook counties) have active acetaminophen-autism cases proceeding under the Frye admissibility standard, which does not apply the same gatekeeping test that closed the federal MDL. Store-brand acetaminophen users have the same legal claims as Tylenol brand users — the failure-to-warn theory applies equally to Walmart's Equate brand, CVS Health brand, Walgreens brand, Costco Kirkland brand, and all other private-label acetaminophen products.
