A pending announcement from the Trump administration linking pain relief drug acetaminophen with autism has stirred investor anxiety in the drug’s primary producer. The share price of Kenvue, the parent company of Tylenol, is down more than 5% on Monday following President Donald Trump’s comments that acetaminophen is “a very big factor” for the risk of autism. Kenvue’s stock is down 25% over the last six months as the company has worked—against investor sentiment—to navigate repeated claims about the pain reliever’s alleged link with autism.

On Sunday during the memorial for slain conservative activist Charlie Kirk, Trump indicated the White House would release information about the cause of autism, including its claimed connection to taking the pain reliever during pregnancy.

“Tomorrow we’re going to have one of the biggest announcement[s]…medically, I think, in the history of our country,” Trump said. “I think you’re going to find it to be amazing. I think we found an answer to autism.”

Department of Health and Human Services Secretary Robert F. Kennedy Jr. has previously espoused a causal connection between autism and acetaminophen, as well as vaccines and environmental toxins. In May, Kennedy vowed to find what caused autism by September, baffling scientists who near-unanimously believe there is no one cause of the condition.

Moreover, numerous public health experts have said there is no evidence proving a causational relationship between acetaminophen and autism. Though early studies found a correlation between Tylenol use during pregnancy and autism, a landmark 2024 study comparing siblings who were and were not exposed to Tylenol in utero largely debunked the link.

The urgency of the administration to find the causes for autism is based on a false idea that greater autism diagnoses is equivalent to a greater prevalence of autism, according to Ari Ne’eman, assistant professor of health policy and management at the Harvard T.H. Chan School of Public Health. Though autism diagnoses have increased by 175% during the past decade, this is likely a function of a better understanding of autism, he said.

“All of this is predicated on the idea that there’s an actual, real increase in not just the diagnosis, but in the actual disability that we call autism,” Ne’eman told Fortune. “There’s very good reason to believe that that is not the case, that what we are actually seeing is a recognition of a population that’s always existed, but previously existed under other names, or in some cases, no name at all.”

A Kenvue spokesperson rebuked the connection between Tylenol and autism, telling Fortune that the drug has long been used as a common pain management and fever-reduction treatment for pregnant women. There are few other safe options for pain relief during pregnancy.

“We believe independent, sound science clearly shows that taking acetaminophen does not cause autism,” the spokesperson said in a statement. “We strongly disagree with any suggestion otherwise and are deeply concerned with the health risk this poses for expecting mothers.”

Kenvue does not report sales specifically for Tylenol, which falls into the self-care segment of the company, but according to analysts at French multinational bank BNP Paribas, the product makes up an estimated 10% of the company’s total revenue.

How MAHA’s announcement could impact Kenvue

Despite stock movement, BNP Paribas analysts aren’t convinced a major linking of Tylenol and autism is bound to have a material impact on Kenvue’s sales. The brand has previously faced scrutiny, including hundreds of lawsuits in 2022 alleging Johnson & Johnson (which manufactured Tylenol before Kenvue split from the company in 2023) and Tylenol’s retailers failed to warn Tylenol’s use during pregnancy would increase the risk of ADHD and autism in children.

A federal judge in December 2023 dealt a hit to hundreds of these lawsuits, barring expert sources from testifying after finding a lack of scientific evidence to back their claims. In August 2024, a federal judge cited that ruling and dismissed the remaining federal cases on the matter. According to Navann Ty, a senior healthcare and biopharma analyst at BNP Paribas, Kenvue’s acetaminophen sales were not implicated by the ongoing legal battle.

“Despite the litigation, we haven’t seen an impact on Tylenol consumption and market share, and they continue to do well,” Ty told Fortune.

Ashley Keller, partner at Keller Postman LLC, will co-lead an appeals case, with a court hearing oral arguments next month. Keller told Fortune the judge’s 2024 dismissal of the cases was a “mistake,” and that the science has evolved to support the argument linking acetaminophen and autism. Keller cited a 2020 University of Washington-led study finding acetaminophen exposure in a baby’s meconium, or its first bowel movement, associated with increased odds of ADHD, as well as research from Andrea Baccarelli, the faculty dean at the Harvard TH Chan School of Public Health.

“The public health community and government officials who organize the public health at the federal level are paying heed to this analysis and are doing the right thing by ensuring that pregnant women get some sort of warning,” Keller said.

According to Ty, the case against Kenvue—as well as the effort to find sufficient evidence of causation between acetaminophen and autism—is an uphill battle that the company from which the company could leave unscathed. Kenvue has previously shaken off investor jitters from similar headlines about a claimed Tytlenol-autism link, including a 14% stock drop following a Wall Street Journal report earlier this month first indicating Kennedy’s plans to draw a causal connection.

“We thought the stock reaction was excessive, given that we think it’s going to be difficult to reopen the [multidistrict] litigation and also to prove causation,” Ty said.

But the difference between the announcement from the Trump administration and the previous litigation is that in 2022 and 2023, primarily the investor community, not consumers, were aware of the litigation against Kenvue, Ty noted. Kenvue may take a hit from the report, should consumers latch onto it.

“Depending on the content of the report and the outreach to consumers, there might be an effect [of the announcement on company sales],” Ty said.