Tylenol orders in pregnant people plummeted after Trump falsely linked the medicine to autism

Tylenol orders in pregnant people plummeted after Trump falsely linked the medicine to autism

By Sara Novak

On September 22, 2025, President Donald Trump held a White House briefing in which he announced that his administration would be notifying doctors that the use of acetaminophen, the active ingredient in Tylenol, was linked to a “very increased risk of autism”—despite evidence to the contrary. Trump instead recommended that pregnant women limit use of the over-the-counter pain and fever reliever only to those times when they couldn’t “tough it out.” During that same briefing, Trump, along with Secretary of Health and Human Services Robert F. Kennedy, Jr., recommended, without evidence, the use of a medication called leucovorin (folinic acid) for the treatment of autism.

In the weeks after Trump’s announcement, the number of pregnant patients in emergency rooms who took paracetamol (another name for acetaminophen that is used internationally) decreased by up to 20 percent, according to an analysis published on Thursday in the Lancet. Researchers noticed no difference in the number of emergency room orders for the medication in nonpregnant patients.

The study also found that the number of children aged fiveto 17 who were prescribed leucovorin as outpatients increased by 71 percent.

On supporting science journalism

If you’re enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.

The researchers included 88,857 pregnant patients and 853,216 nonpregnant patients in the analysis. The findings suggest that the Trump administration’s announcement had a notable effect, though it’s unclear from the data whether orders for acetaminophen changed because of patients refusing the pain reliever or physicians making a clinical decision. Experts say it was likely a combination of both.

“Directly after this press conference, thousands of women who would have had their fever or pain treated did not, based on false statements and mischaracterizations of data from the White House,” says study co-author Jeremy Faust, an emergency physician at Brigham and Women’s Hospital and an assistant professor at Harvard Medical School.

High-quality studies have shown that acetaminophen is the safest available pain reliever and fever reducer to take during pregnancy. Furthermore, untreated fever during pregnancy carries a host of risks to the fetus, including miscarriage, birth defects and premature birth. Fevers during pregnancy have also been linked to an increased likelihood of autism in offspring.

The most consequential study of acetaminophen use during pregnancy and autism rates in children, published in JAMA in 2024, followed nearly 2.5 million children in Sweden from 1995 to 2019; it accounted for the genetic risk of autism by comparing siblings. The study found no evidence of an increased likelihood of autism or attention deficit hyperactivity disorder (ADHD) tied to use of acetaminophen. “Within siblings where the mother took acetaminophen during one pregnancy but not during another, the siblings still shared the exact same autism and ADHD risk,” says Brian Lee, senior author of the JAMA study and an epidemiologist at Drexel University.

It’s unclear from the Lancet study whether pregnant patients got a different medication or if they went without. Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen and aspirin are not considered safe during pregnancy because of they can result in low amniotic fluid and an increased risk of birth defects. And opioids carry a risk of addiction in the pregnant person and in the baby after birth and can cause withdrawal symptoms in the latter.

As for leucovorin, the medication Trump and his FDA promoted for autism treatment, Lee says that studies showing the drug’s effectiveness are “provisional at best.” The largest study of the medication included only 77 children and was retracted in January because of errors in its data analysis.

“Words matter, and patients and providers want to be able to trust the guidance coming from our governmental institutions,” says Jennifer Braverman, a maternal and fetal medicine physician at University of Colorado Medicine, who was not involved in the study. She adds that as a result of Trump’s announcement, a lot of pregnant women were either given something less safe or just told to muddle through. “It’s very dismissive of women’s pain and suffering,” she says.

It’s Time to Stand Up for Science

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.

I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.

If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.

In return, you get essential news, captivating podcasts, brilliant infographics, can’t-miss newsletters, must-watch videos, challenging games, and the science world’s best writing and reporting. You can even gift someone a subscription.

There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.