By Zachary Stieber
The manufacturer of Tylenol was keeping tabs on research into the drug and neurodevelopmental issues such as autism, and concluded in 2018 that evidence of a link between them was becoming significant, according to newly disclosed documents.
In a Feb. 8, 2018, email obtained by The Epoch Times, Rachel Weinstein, director of epidemiology at Johnson & Johnson subsidiary Janssen, wrote, “The weight of evidence is starting to feel heavy to me.”
Weinstein was emailing Jesse Berlin, Johnson & Johnson’s global head of epidemiology, about a review that concluded that nine studies suggested that use of acetaminophen—the active ingredient in Tylenol—by pregnant women was linked to autism and other neurodevelopmental issues in the women’s children.
Weinstein said that Janssen had been discussing with a neurologist about how acetaminophen could be beneficial.
“But now we’ve added the studies in prenatal exposure and neurodev [sic] outcome,” she said.
Berlin wrote that he read the review and that “there appears to be some specificity of the association.” While he took issue with how some papers did not analyze other drugs, “at least one study looked separately at specific indications and the association didn’t go away,” he said.
Johnson & Johnson was the maker of Tylenol for years. In 2023, a newly created company called Kenvue took over the Tylenol brand and other consumer brands.
“These documents show we were doing exactly the right thing,” a spokesperson for Kenvue told The Epoch Times in an email. “We have continuously evaluated the science, and there is no credible evidence that taking acetaminophen causes autism.”
‘Difficult Options’
Dr. Jørn Olsen of Aarhus University in Denmark and other researchers in 2014 released an observational study that determined maternal acetaminophen use during pregnancy was linked to a higher risk of attention-deficit/hyperactivity disorder-like behavioral problems or hyperkinetic disorders in their children.
Weinstein, in an email, told Olsen that the study had strengths but wondered whether the researchers had tried assessing any association between other drugs pregnant women take, such as aspirin, and the disorders. Olsen, in a brief reply, said the researchers planned to look at those drugs in future studies.
Weinstein forwarded the email to the company’s consumer medical safety division.
“Recall that we have ruled out the possibility of conducting a database study of our own because other existing databases would be underpowered to detect the same effect that the Danish study found, due to the lack of a large enough database,” she wrote in her email.
She asked whether the question for the company was whether there was a willingness to support Olsen “up to a reasonable amount with the provision that the investigator has final say on publication but the sponsor can review and comment on the manuscript prior to publication.”
Weinstein told Berlin that there were several options, including funding Olsen. They could also try to replicate Olsen’s study, conducted in Denmark, with Norwegian data on prescriptions and diagnoses, and by including other drugs.
“The outcome of such a study is unknown. We could end up confirming the Danish findings, for example,” she said.
She later drafted a note to Olsen that initially said Johnson & Johnson would be happy to work with him on additional research. Berlin in response proposed revisions. But Weinstein then told Berlin she was having second thoughts on engaging Olsen.
“Do we really need to stick our neck out and make this offer? Would we be surprised if the new analyses confirmed or did not confirm the existing studies?” she asked.
Berlin responded: “I’m trying to think through what we would do based on what we learn. I don’t have a huge problem abandoning this, if that’s where we end up after talking.”
Weinstein, who is now retired, could not be reached for comment. Berlin, now a professor at Rutgers University, did not respond to a request for comment.
Internal slides from around the time of the emails, obtained by The Epoch Times, stated that the company declined to pursue a collaboration with Danish researchers in part because executives were unsure about “the value to pregnant consumers,” who might be presented with “difficult options” such as “don’t use anything if you have a fever.”
Lawyer: ‘Irresponsible’
The emails came to light in lawsuits brought by women who say they should have been warned by Johnson & Johnson and retailers about the risks of neurodevelopmental problems associated with acetaminophen products.
The women have pointed to papers such as a 2020 prospective study in Canada that found an increased risk of ADHD among children born to women who used acetaminophen while pregnant.
“Drugmakers have a legal and ethical obligation to continually investigate the safety of their products. Yet despite recognizing the heavy weight of the scientific evidence years ago, Kenvue scientists made a deliberate decision not to ’stick our necks’ out to commission further research,” Ashley Keller, senior partner at law firm Keller Postman, which is representing the women in multiple cases, told The Epoch Times via email.
“The reason for that irresponsible choice is obvious. The company didn’t study the question for fear they would not like the answer. But pregnant moms deserve answers, and protecting a multi-billion dollar drug franchise is no excuse for ostrich-like corporate misbehavior.”
The emails were first reported by the Daily Caller and drewtheattention of the White House and the Department of Health and Human Services.
Government officials recently warned the public that Tylenol use during pregnancy may be associated with autism in children born to the mothers.
‘We Have Been Looking at It’
Weinstein said in a 2023 deposition that it would be unethical to run a randomized, controlled trial seeking to figure out whether there was a link between in utero acetaminophen exposure and neurodevelopmental problems. It would be good to do “more tightly controlled” observational studies, or research utilizing sources such as medical claims databases, she said.
Weinstein also said that Johnson & Johnson had been tracking literature on the topic for nearly a decade, including epidemiological, safety, and preclinical studies.
She said that the company has “essentially done a systematic review,” or an analysis of strong studies on the matter.
She said the company would be publishing the review but did not know when.
Internal slides from 2018, obtained by The Epoch Times, described the results of a company analysis of 16 studies regarding prenatal exposure to acetaminophen and neurodevelopmental disorders.
The slides stated that individual observational studies “show a somewhat consistent association of increased occurrence of neurodevelopmental outcomes with prenatal exposure,” with strengths including some studies being prospective. Limitations included researchers measuring children at different ages, such as 18 months and seven years.
A 2022 internal Kenvue slide deck stated that 12 studies featuring clinically diagnosed endpoints were analyzed. The studies were “too limited in methodological or analytical design to draw conclusions regarding a causal relationship between prenatal acetaminophen use and adverse neurodevelopmental outcomes in children,” and therefore, if acetaminophen is used as directed, it is safe to use during pregnancy, the slide deck stated.
A review coauthored by Kenvue scientists and funded by Kenvue was published by Critical Reviews in Toxicology in February.
The authors of the review said that they reviewed preclinical studies and determined that the data “demonstrates no consistent evidence of adverse effects following developmental exposure to acetaminophen at therapeutic and/or non-systemically toxic doses on the structure and function of the nervous system, including neuroanatomical, neurotransmission, and behavioral endpoints.”
Labeling Change
Other documents labeled the effort to study the matter Project Cocoon, stated that Weinstein was involved, and listed as the mission of the project “to protect acetaminophen.”
One slide stated, “Courage: We don’t need a label change.”
The label of Tylenol has long stated, “If pregnant or breastfeeding, ask a health professional before use.”
In 2017, one document showed that the company changed its internal label to add, “This product should not be used during pregnancy or lactation unless the potential benefit of treatment to the mother outweighs the possible risks to the developing fetus/nursing infant.”
When asked in a 2023 deposition about whether the change means doctors could give patients guidance on potential risks of developmental outcomes, Leslie Shur, Johnson & Johnson’s director of pharmacovigilance, replied, “and the risk of, in the case of fever … of not treating.”
The U.S. Food and Drug Administration said on Sept. 22 that it has started the process to change the label for Tylenol and other acetaminophen-containing products “to reflect evidence suggesting that the use of acetaminophen by pregnant women may be associated with an increased risk of neurological conditions such as autism and ADHD in children.”
Regulators said a causal relationship has not been established and noted that acetaminophen is the only over-the-counter drug available to treat fevers in pregnancy.
The FDA in 2014 had decided to take no regulatory action, following advice from reviewers. In 2016, FDA reviewers said, “With growing evidence for adverse neurodevelopmental outcomes being associated with in utero [acetaminophen] exposure, even in the absence of proof of a causal relationship, it would be appropriate for FDA to bring this issue to the attention of consumers and health care providers through one of the communication avenues available to the agency.”
Reviewers in 2019 said data indicated that prenatal acetaminophen exposure “is not necessary completely benign for the fetus” and “it would be desirable for the agency to communicate this message to healthcare providers and pregnant women, considering that acetaminophen is so commonly used by women during their pregnancies, and that many perceive acetaminophen to be risk-free.”
Court Cases
U.S. District Judge Denise Cote dismissed the federal multidistrict litigation over acetaminophen in 2024, after finding that experts offered by the plaintiffs misrepresented the results of studies.
The case was appealed and is set for oral argument before an appeals court on Nov. 17, after being delayed from a date in early October.
Keller and other attorneys in a recent filing alerted the court to the government’s move to update Tylenol’s label. The filing noted that government officials quoted one of the plaintiffs’ witnesses, Dr. Andrea Baccarelli, dean of the faculty at the Harvard TH Chan School of Public Health, who said that, in his expert opinion, “there is a causal relationship” between prenatal acetaminophen exposure and neurodevelopmental disorders.
“Expert opinion that is sound enough to persuade every Senate-confirmed federal scientist easily clears Rule 702(d)’s bar,” or the rule governing expert witnesses in litigation, they wrote. Attorneys for Kenvue told the court that statements from the government and Baccarelli “confirm that the existing evidence does not support a causal relationship.”
In California, a state judge in May turned away a similar case, concluding that evidence on the link between prenatal acetaminophen exposure and autism is “profoundly uncertain and conflicting.”
The judge also wrote that slides and other internal documents showed “candid internal discussion,” which she described as “positive corporate behavior.”
An appeal in that case is ongoing.
