Tylenol Is Tied to Autism, Texas Claims in Suit. Kenvue Stock Shudders.

Kenvue makes Tylenol, whose active ingredient is acetaminophen. (Justin Sullivan/Getty Images)

Key Points

• Texas filed a lawsuit against Kenvue and Johnson & Johnson, alleging deceptive advertising regarding Tylenol’s safety during pregnancy.
• The lawsuit claims Tylenol’s active ingredient, acetaminophen, is linked to autism, citing small studies and a Trump administration warning.
• Kenvue’s shares fell 3.2% following the lawsuit and have dropped 40% since May due to slowed growth and autism allegations.

Texas joined the Trump administration in claiming Tylenol causes autism.

Shares of Kenvue fell 3.2% Tuesday to $14.60 after Texas Attorney General Ken Paxton filed a suit alleging that the maker of Tylenol engaged in deceptive advertising that said the over-the-counter drug was safe to use while pregnant. The suit also named Johnson & Johnson , which spun off Kenvue in 2023.

The complaint cited small studies that concluded Tylenol’s active ingredient, acetaminophen, is linked to autism when taken in pregnancy or early childhood. President Donald Trump and Health Secretary Robert F. Kennedy Jr. pointed to the studies in September when they put out an official warning that acetaminophen is a potential cause of autism.

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In a statement, Kenvue said it would defend itself against “these baseless claims.”

“We stand firmly with the global medical community that acknowledges the safety of acetaminophen and believe we will continue to be successful in litigation as these claims lack legal merit and scientific support,” the company said.

Scientific studies of possible harms from acetaminophen in pregnancy have reached conflicting conclusions, and been burdened by the paucity of good medical records on people’s use of an over-the-counter product.

For his claim that acetaminophen causes autism, Paxton cites older studies—such as a 2013 report in a herbal medicine journal. That study’s publisher qualified its conclusions in September 2025, noting more recent, large controlled studies that found no association between autism and the drug. The largest, best-controlled studies—one in Sweden and one in Japan— found no association.

Shares of Kenvue have fallen 40% since early May as growth has slowed for the heir to J&J’s consumer products business and the Trump administration added Tylenol to its catalog of medicines alleged to cause autism. Class-action suits have also claimed that Kenvue and J&J knowingly sold baby powder contaminated with the carcinogen asbestos, which Kenvue denies.

With Kenvue shares well below the $25.53 price at which they debuted in 2023, the company has become the object of activist investors such as Starboard Value, TOMS Capital, and Third Point Management. They argue that the company can sell its skin care and beauty products, or the entire company, to another company.

Under pressure, Kenvue replaced its chief executive in July and hired consultants to conduct a strategic review.

J&J’s response to the claims against Kenvue is that J&J transferred responsibility for those products, and any purported liabilities, to the spunoff company.

That transfer of legal responsibility, Texas alleges in its Tuesday lawsuit, was a key motivation for the spinoff.

Write to Bill Alpert at william.alpert@barrons.com