The Trump administration made two substantial policy recommendations on Monday: The first was to limit the use of Tylenol (the brand name for the generic drug acetaminophen), the only over-the-counter pain reliever considered safe for pregnant women, during pregnancy. The second was to approve the use of folinic acid to treat speech disorders related to autism. Though there are some reasons to caution the use of acetaminophen during pregnancy, there is currently no reliable publicly available evidence that shows a causal link between its consumption in pregnancy and the development of autism.
In their public statements, Trump and Kennedy also frequently went beyond the qualifier-laden pronouncements of other top health officials. “Taking Tylenol is not good. All right, I’ll say it. It’s not good,” said Trump during Monday night’s briefing, flanked by Kennedy, Centers for Medicare and Medicaid Services Administrator Dr. Mehmet Oz, Food and Drug Administration Commissioner Dr. Martin Makary, and National Institutes of Health Director Jay Bhattacharya.
The three health agency heads were more measured in their Monday opinion piece in Politico, writing that “observational evidence has suggested that when moms take acetaminophen during pregnancy, especially close to delivery, it is correlated with subsequent diagnosis of conditions like autism and ADHD,” but also state that “evidence from family control studies have failed to find a correlation.” They concluded that acetaminophen should be used “judiciously” in pregnancy, with “caution extended to infants and toddlers.”
Trump seemed to think that those recommendations didn’t go far enough. “Don’t take Tylenol if you’re pregnant and don’t give Tylenol to your child when he’s born or she’s born,” he said near the end of the press conference. “Don’t give it, just don’t give it.”
But acetaminophen is the only pain reliever considered safe for pregnant women to use. Other over-the-counter medications like aspirin, ibuprofen, and naproxen—all nonsteroidal anti-inflammatory drugs—can harm the developing fetus, especially if taken later in a pregnancy.
Some medical authorities pushed back on the administration’s claims. “The conditions people use acetaminophen to treat during pregnancy are far more dangerous than any theoretical risks,” noted Dr. Steven J. Fleischman, the president of the American College of Obstetricians and Gynecologists (ACOG), in a Monday press release citing the risks of conditions like maternal fevers to unborn children. He also noted that no study had yet successfully documented a causal link between acetaminophen use in pregnancy and autism.
Sen. Bill Cassidy, a Republican and doctor from Louisiana who chairs the Senate’s health committee, was also skeptical. “HHS should release the new data that it has to support this claim. The preponderance of evidence shows that this is not the case,” he wrote on X. “The concern is that women will be left with no options to manage pain in pregnancy.”
Kenvue, the maker of Tylenol, understandably went into corporate crisis management mode. “We understand the recent media coverage you’re reading may cause concern or lead to questions,” the company says on it website. “If you are treating your little one with acetaminophen, please know that there is no credible science that shows taking acetaminophen causes autism,” it continued citing statements from ACOG, the Society for Maternal-Fetal Medicine, the American College of Pediatrics, and the Autism Science Foundation.
Though Kenvue’s stock fell 16 percent on September 5 after a Wall Street Journal report previewed Kennedy’s upcoming pronouncements, it started to rebound after slumping on Tuesday, as it became clear that the White House was not announcing any new scientific evidence demonstrating Tylenol’s dangers, nor bans or FDA label changes. The Wall Street Journal later reported that Kenvue’s CEO privately met with RFK Jr., hoping to persuade him not to cite Tylenol in any pronouncements.
The White House was not pulling its claims about Tylenol out of thin air. Dr. Andrea Baccarelli, the dean of Harvard University’s T.H. Chan School of Public Health, noted Tuesday that a recent review of 46 studies he conducted found an “association” between Tylenol use in pregnancy and autism, especially when used for more than four weeks. “I believe that caution about acetaminophen use during pregnancy—especially heavy or prolonged use—is warranted,” he said in a statement. “Patients who need fever or pain reduction during pregnancy should take the lowest effective dose of acetaminophen, for the shortest possible duration, after consultation with their physician.”
“That’s been the advice for decades,” Renee Gardner—a principal researcher specializing in epidemiology at the Karolinska Institutet, a Swedish-based medical research university—told TMD. “It’s not like women are going about and sort of recreationally taking large doses of acetaminophen during pregnancy all of a sudden.”
Gardner was a co-senior author of an April 2024 study that examined potential links between acetaminophen intake during pregnancy and the development of early childhood neurodevelopmental disorders, including autism, using Swedish public health data of nearly 2.5 million children born in the country between 1995 and 2019. And, while they found an association between acetaminophen use and neurodevelopmental disorders, there was no link when they applied a sibling control, in which they compared siblings in cases where the mother used acetaminophen during one pregnancy but not the other.
“Multiple biases may explain” the correlation between acetaminophen use and autism some studies have noted, including the underlying reasons a pregnant woman would take the drug, such as an infection or fever, and genetics, which Gardner said “is one of the most important factors in terms of determining whether a person has autistic traits or not.” Still, the 2024 study found “there was not one single ‘smoking gun’” responsible for the association without the sibling control groups. “Despite what the administration would really like, there are no easy sort of explanations for this,” Gardner said. “We’re, after all, trying to describe really complex human traits here.”
The Trump administration also said the FDA was approving a new treatment for some autism symptoms: leucovorin, also known as folinic acid, used to treat some side effects of cancer treatment. “Our research has revealed that folate deficiency in a child’s brain can lead to autism,” Kennedy said on Monday. Folate is also known as Vitamin B9, and there is some evidence that treating children with autism spectrum disorder with folate can improve speech disorders. “We have a duty to let doctors and the public know,” Makary said. “Hundreds of thousands of kids, in my opinion, will benefit.”
But as with Tylenol, the administration’s Politico piece was much more guarded than statements made at Monday’s press conference. “Leucovorin is not a cure for autism but has demonstrated an improvement in speech-related deficits for autism,” wrote the administration officials.
“Treatments post-birth are always to be viewed with skepticism” because of autism’s strong genetic component, Dr. Paul Offit, the director of the Vaccine Education Center at the Children’s Hospital of Philadelphia, told TMD. “The data that President Trump and RFK Jr. were arguing for were thin at best.” Offit noted the long history of supposed treatments for autism that have failed to pan out: the hormone secretin, nicotine patches, Lupron (the drug used to chemically castrate sex offenders), antifungal medication, raw camel milk, and even dolphin therapy. “I just feel sorry for these parents who are so often misled here,” he said. Though the public faces of autism, like Elon Musk, have a moderate, socially functional level, being severely autistic is debilitating, for both the people themselves and the families who support them.
Administration officials presented the prevalence of autism as an emergency requiring a rapid response. During the press conference on Monday, both Kennedy and Bhattacharya referred to autism in the U.S. as an epidemic of increasing proportions. “You’re only seeing this in people who are under 50 years of age,” said Kennedy, rebutting claims that rising rates of autism were due to changing diagnostic criteria. “I’ve never seen this happening [profound autism] in people my age.”
But that doesn’t necessarily mean autism is becoming more prominent, only that autism diagnoses are. Several decades ago, “The autism diagnosis was generally not given to people who showed the kind of profound impairments that profoundly autistic people have,” Helen Tager-Flusberg, professor emerita in psychological and brain sciences at Boston University and founder of the Coalition of Autism Scientists, told TMD. “So in his day, yes, there wouldn’t have been people with that diagnosis, because it sort of didn’t exist for people who meet the criteria for profound autism.”
Trump also pointed to Cubans and the Amish to back his claims. “They don’t have Tylenol, and I hear they have essentially no autism,” he said of the Caribbean island nation. “[Autism] doesn’t exist with the Amish community, and they don’t take all of this junk,” he added, referring to the higher likelihood of Amish people to eschew vaccines and use alternative medicine. But Tager-Flusberg maintains these are likely examples of certain groups not looking to diagnose the condition the way the broader U.S. community has in recent years: “I suspect it’s the same case of, well, if we’re not out there looking for it, we say that it doesn’t exist.”
The White House is confident in its proclamations, though, and Monday’s press conference made clear administration officials don’t plan to slow down on making more potentially controversial pronouncements. “We are now replacing the institutional culture of politicized science and corruption with evidence-based medicine,” Kennedy said.
