Is there a Tylenol Lawsuit Over Autism?

Yes. Tylenol (acetaminophen) lawsuits are being filed against Johnson & Johnson, its spin-off Kenvue Inc., and major retailers like Walmart, CVS and Walgreens, alleging they failed to warn that using the painkiller during pregnancy could increase the risk of children developing autism spectrum disorder (ASD).

The lawsuits claim that retailers and manufacturers of acetaminophen falsely marketed the drug as safe and failed to warn pregnant women about the neurological risks their children could face after in-utero exposure.

2026 Tylenol Lawsuit Status

Federal Tylenol autism and ADHD lawsuits were consolidated in October 2022 as part of multidistrict litigation in the U.S. District Court for the Southern District of New York, where U.S. District Judge Denise Cote was assigned to oversee coordinated discovery and pretrial proceedings. The claims allege that manufacturers and retailers failed to adequately warn pregnant women about research suggesting prenatal exposure to acetaminophen may increase the risk of autism spectrum disorder and attention deficit hyperactivity disorder in children.

The federal litigation suffered a major setback in late 2023 and early 2024, after Judge Cote excluded key plaintiffs’ expert witnesses who were expected to testify about whether acetaminophen exposure during pregnancy can cause autism and ADHD. Without that testimony, more than 500 lawsuits were dismissed in February 2024 before any bellwether trials could take place. Plaintiffs appealed the ruling to the U.S. Court of Appeals for the Second Circuit.

In July 2026, the Second Circuit reversed the expert witness ruling and reinstated the dismissed Tylenol autism and ADHD lawsuits, finding that several of the plaintiffs’ experts used accepted scientific methodologies and should have been permitted to present their opinions to a jury. The cases are now being returned to Judge Cote for further proceedings, and the ruling has also opened the door for additional families to file new claims. No bellwether trials have occurred, but the renewed litigation may ultimately return to a process for selecting representative cases for early trial dates.

As of August 2026, the Tylenol autism and ADHD litigation has been revived and is moving back into coordinated proceedings in the Southern District of New York following the federal appeals court ruling. Lawyers are again investigating and pursuing claims for families of children diagnosed with autism or severe ADHD following prenatal exposure to Tylenol or other acetaminophen products.

Can Tylenol Cause Autism?

More than two dozen peer-reviewed studies have reported consistent associations between prenatal acetaminophen exposure and increased rates of autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD), yet families and expected mothers were not adequately warned about the potential risk for decades.

What is Tylenol and How It Works

Acetaminophen is the active ingredient in Tylenol and many other over-the-counter pain relief and fever reduction medications. It works primarily by inhibiting prostaglandin production in the central nervous system. Prostaglandins are lipid compounds that help transmit pain signals and contribute to fever responses. By reducing prostaglandin activity, acetaminophen lowers pain and helps bring down elevated body temperature.

Acetaminophen’s fever-reducing effects come from its action on the hypothalamus, the part of the brain that regulates body temperature. By influencing this thermoregulatory center, the medication helps reduce fever while also easing discomfort associated with illness.

Theories on How Acetaminophen May Influence Autism Risks

Researchers have proposed several biological mechanisms to explain why prenatal acetaminophen exposure has been consistently associated with higher rates of autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD) in studies. Since acetaminophen crosses the placenta and reaches the developing fetal brain, where the blood–brain barrier is still immature, some scientists believe it may affect pathways involved in neurodevelopment, including prostaglandin regulation, oxidative stress responses, and endocannabinoid signaling.

Studies have found children born with elevated levels of acetaminophen in their cord blood had higher rates of developing autism. Supportive studies have found children exposed to Tylenol during pregnancy were 19% more likely to have autism spectrum disorders and 21% more likely to have ADHD symptoms compared to non-exposed children.

Are Tylenol ADHD Lawsuits Being Pursued?

Our product liability lawyers are actively pursuing lawsuits for families of children who have been diagnosed with Autism, or both Autism and ADHD, following prenatal exposure to acetaminophen based drugs.

Tylenol Autism Litigation

Amid mounting evidence linking a mothers use of acetaminophen products during pregnancy to a child’s increased risk of developing autism and ADHD, a growing number of Tylenol autism lawsuits and Tylenol ADHD lawsuits were filed by families across various U.S. District Courts nationwide.

Each of the claims raised similar allegations that the defendants knew or should have known that prenatal exposure to acetaminophen may increase the risk of autism or ADHD, yet failed to provide adequate warnings and continued marketing the drugs as safe for use during pregnancy.

Tylenol Autism Multidistrict Litigation (MDL)

In October 2022, the U.S. Judicial Panel on Multidistrict Litigation ordered all federal Tylenol autism and ADHD lawsuits to be centralized before Judge Denise L. Cote in the Southern District of New York. At the time, dozens of families had filed claims alleging that prenatal exposure to acetaminophen increased the risk of children developing autism spectrum disorder or attention deficit hyperactivity disorder.

Centralization was intended to streamline the litigation, avoid inconsistent rulings, and allow both sides to focus on whether scientific evidence could reliably show that acetaminophen use during pregnancy is capable of causing a neurodevelopmental disorder. The MDL court was tasked with evaluating this “general causation” evidence before any individual claims could proceed to discovery or trial.

By early 2023, a master complaint, short-form complaint system, and coordinated discovery plan were in place, positioning the litigation for expert challenges that would ultimately determine whether the science supporting plaintiffs’ claims was legally admissible.

Exclusion of Plaintiffs’ General-Causation Experts

In December 2023, Judge Cote issued a landmark ruling excluding all of the plaintiffs’ general-causation experts. After reviewing the testimony of epidemiologists, toxicologists, and neurologists offered by plaintiffs, the court found that the opinions failed to meet the reliability requirements of Federal Rule of Evidence 702.

The ruling concluded that the plaintiffs’ experts selectively relied on observational studies, failed to apply consistent scientific methodologies, and did not adequately account for confounding factors that could influence the association between acetaminophen use and neurodevelopmental disorders. Without admissible expert testimony, plaintiffs could not prove that prenatal exposure to acetaminophen is capable of causing autism or ADHD.

Following the exclusion of expert testimony, the court issued summary judgment in favor of Johnson & Johnson, Kenvue, Walmart, CVS, Walgreens, and other defendants. In February 2024, approximately 500 filed cases were dismissed in a single final judgment.

The decision effectively ended the federal litigation at the trial-court level, as general causation is a foundational element in any product liability claim involving alleged medical injuries.

Federal Tylenol Autism Lawsuits Could Be Revived

However, plaintiffs have appealed Judge Cote’s rulings to the U.S. Court of Appeals for the Second Circuit, challenging both the exclusion of expert testimony and the summary judgment dismissal that followed. The appeal argues that:

• The district court applied an overly rigid interpretation of the federal evidence rules
• The judge improperly weighed the scientific evidence instead of assessing admissibility
• The consistency of the observational studies was sufficient to allow a jury to consider the science

If the Second Circuit reverses the decision, the Tylenol autism and ADHD lawsuits could be reinstated, allowing general-causation issues to proceed to trial or renewed expert evaluation. Until the appellate court issues its ruling, the federal litigation remains paused, although some state-court cases continue independently.

2025 HHS Tylenol Autism and ADHD Warnings

In September 2025, the U.S. Department of Health and Human Services (HHS) issued a press release outlining new acetaminophen pregnancy-related guidance, which recommended stronger warnings on all medications containing acetaminophen, including Tylenol and store-brand generics. This marked the first time a major federal health agency formally acknowledged that prenatal acetaminophen exposure may pose neurodevelopmental risks to unborn children.

Although acetaminophen has long been considered the pain reliever safest for use during pregnancy, HHS cited a growing body of research showing consistent associations between prenatal exposure and increased rates of autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD). The updated guidance recommends that pregnant individuals:

• Use acetaminophen only when medically necessary
• Use the lowest effective dose for the shortest possible duration
• Speak with a healthcare provider before taking any over-the-counter acetaminophen product

HHS Warning Highlights Autism and ADHD Risks

HHS referenced multiple epidemiological studies involving hundreds of thousands of mother-child pairs, including research showing:

• Acetaminophen and its metabolites cross the placenta
• These compounds have been detected in umbilical cord blood, demonstrating fetal exposure
• Acetaminophen can cross the fetal blood–brain barrier, which is not fully developed and therefore more vulnerable to disruption
• Higher concentrations of acetaminophen metabolites in cord blood were associated with a 3-fold increase in ADHD and nearly a 4-fold increase in autism
• Large cohort studies reported 19 percent higher autism rates and 21 percent higher ADHD rates among exposed children

While HHS emphasized that current evidence does not establish a definitive causal link, the agency warned that the consistency of the associations, combined with plausible biological mechanisms, warrants greater precaution during pregnancy.

Studies Linking Tylenol to Autism & ADHD Risks

Autism and ADHD are two distinct conditions, however, they are both part of a larger group of neurological disorders that impact impulses, behavior and focus.

In fact, research has found symptoms of the conditions often coexist, with as many as 50% to 70% of individuals with autism spectrum disorder meeting the criteria for ADHD, and as many as 50% of those with ADHD showing signs of autism.

While the exact method in which both conditions coexist has not been fully established, over the last decade more than two dozen studies have found a consistent link between the use of name brand and generic acetaminophen and autism spectrum disorder and attention deficit disorder.

Acetaminophen Linked to Autism & ADHD Side Effects

A 2021 study published in the European Journal of Epidemiology found that Tylenol exposure during pregnancy may increase the likelihood a child will be on the autism spectrum or have symptoms of attention deficit hyperactivity disorder (ADHD).

The study reviewed data from more than 73,000 mother-child pairs focusing on prenatal and postnatal use of acetaminophen up to 18 months after birth.

According to the findings, researchers indicated children exposed to Tylenol during pregnancy were 19% more likely to have autism spectrum disorders and 21% more likely to have ADHD symptoms compared to non-exposed children.

ADHD and Autism from Acetaminophen in Cord Blood

A 2019 study published in the medical journal JAMA Psychiatry found children with the highest levels of acetaminophen in their cord blood at the time of birth have a higher risk of neurological disorders.

The study compared levels of generic acetaminophen in each infant umbilical cord plasma sample collected at birth. Researchers discovered children with the highest levels of acetaminophen in their cord blood were nearly three times as likely to have been diagnosed with ADHD and nearly four times as likely to have autism.

Acetaminophen ADHD Risk Increased 41%

A 2016 study published in the International Journal of Epidemiology suggested even a single use of acetaminophen during pregnancy could increase a child’s risk of developing ADHD by 41%, and could also increase the risk of autism spectrum disorder.

Prenatal Tylenol Exposure Side Effects

A 2014 study published in JAMA Pediatrics discovered a possible link between Tylenol and ADHD, as well as hyperkinetic disorders (HKDs), which is a disease that can cause excessive involuntary movements.

Researchers reviewed data on 64,322 children and mothers who used acetaminophen during pregnancy. Their findings indicate fetal exposure to acetaminophen was 29% more likely to cause ADHD, and 37% more likely to cause HKD by the age of seven.

Tylenol ADHD Risks Per Trimester

A study published in the medical journal Pediatrics in 2017 discovered pregnant women taking any amount of generic acetaminophen during pregnancy caused a 7% increased risk of ADHD in the first trimester, and a 27% increased risk during the third trimester.

Researchers further found the chances of a child developing ADHD more than doubled if pregnant women used acetaminophen for more than 29 days. Those who used acetaminophen for 22 to 28 days for fever and infection were linked to a six-fold increased risk of their child developing ADHD.

Are There Any Costs to Hire a Tylenol Autism Lawyer?

There are absolutely no out-of-pocket costs to review your case or hire our attorneys. Potential claims are evaluated for individuals throughout the United States, and all cases are handled on a contingency fee basis.

Through the use of contingency attorney fees, individuals have access to the experience and resources of our national law firm for their Tylenol lawsuit — regardless of their individual financial resources.

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