The question of whether the Supreme Court is ready to hear autism lawsuits against pharmaceutical companies, particularly those involving claims that drugs like Tylenol (acetaminophen) cause autism, is complex and evolving. As of 2025, these lawsuits are actively progressing through various levels of the judicial system, but the Supreme Court has not yet taken up such cases directly.
At the heart of these lawsuits is the allegation that prenatal exposure to acetaminophen increases the risk of autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD). Plaintiffs argue that pharmaceutical companies failed to warn consumers adequately about these potential risks, which forms the basis of product liability claims centered on “failure to warn.” These claims have been brought against major manufacturers like Johnson & Johnson and retailers selling acetaminophen products.
The litigation landscape has seen significant activity, particularly in federal multidistrict litigation (MDL) and state courts. The federal MDL, based in the Southern District of New York, faced a major setback in late 2023 when a judge excluded plaintiffs’ expert testimony on causation under the Daubert standard, which requires scientific evidence to be reliable and relevant. This ruling led to the dismissal of many federal cases, leaving them in limbo as plaintiffs appealed the decision. The appeal process is ongoing, with oral arguments heard but no final ruling yet, meaning the federal litigation remains unresolved.
Meanwhile, state court cases in places like California, Illinois, Pennsylvania, and New Jersey are advancing more steadily. These courts often apply different standards for admitting expert testimony, such as the Frye standard, which can be more permissive than Daubert. This has allowed some cases to move closer to trial, with new expert reports and scientific studies being introduced to support claims of causation. These developments suggest that while federal courts have been cautious, state courts may provide a more favorable venue for plaintiffs.
The scientific evidence linking acetaminophen to autism remains controversial and inconclusive. Studie
