Health and Medicine
PUBLISHED
On September 22, 2025, President Trump held a press briefing in which he gave pregnant Americans a simple message: “Don’t take Tylenol.” Scientists and science communicators – including yours truly – were quick to point out the lack of good evidence to back up this position, as well as the potentially harmful consequences of this controversial advice. Now, it’s emerged that ER doctors in the US have appeared to be less willing to order Tylenol for pregnant patients since that briefing.
The rest of this article is behind a paywall. Please sign in or subscribe to access the full content.Tylenol prescriptions for pregnant ER patients down 10 percent
New data collected from electronic health records from almost 300 million patients, covering a period up to November 2025, shows the real-world consequences of Trump denouncing this drug. After the briefing on September 22, the authors of this new study observed that emergency department orders for acetaminophen – the active ingredient in Tylenol – decreased by 10 percent for pregnant patients aged 15-44.
Acetaminophen, or paracetamol, is an over-the-counter pain reliever and fever reducer. It’s often the first-choice drug due to its excellent safety record. Crucially to this story, it’s also really the only drug in this category that is considered safe for use in pregnancy, leaving pregnant people who fall sick with few other options.
In real life, the risk–benefit decision is rarely ‘medicine versus nothing’. It’s medicine versus ongoing symptoms and the condition causing them.
Professor Asma Khalil
Last year, as well as Trump’s far less measured language in the press briefing, the Food and Drug Administration (FDA) announced a labeling update for acetaminophen-containing products. They said the aim was to “reflect evidence suggesting [its use] by pregnant women may be associated with an increased risk of neurological conditions such as autism and ADHD in children.”
FDA Commissioner Marty Makary, MD, MPH, spoke about a “considerable body of evidence” to support this move. However, many experts from around the world were quick to point out that this evidence base was flawed, and that the best quality studies had found no reason for pregnant people to stop using Tylenol.
In January of this year, a huge systematic review and meta-analysis was published, which confirmed that there was no good evidence to suggest that Tylenol use in pregnancy was associated with autism, ADHD, or intellectual disability. Senior author Professor Asma Khalil told IFLScience that this approach is considered “the gold standard”, and independent experts agreed.
The issues with the fearmongering around Tylenol in pregnancy extend beyond the unnecessary anxiety this could cause expectant parents.
“Fever in pregnancy is often a sign of infection, and untreated fever (and the underlying illness) can be associated with adverse pregnancy outcomes. In real life, the risk–benefit decision is rarely ‘medicine versus nothing’. It’s medicine versus ongoing symptoms and the condition causing them,” Professor Khalil told IFLScience.
“The sensible advice remains to use the lowest effective dose for the shortest necessary time, and to seek medical advice if symptoms are severe, persistent, or accompanied by features such as a high temperature that doesn’t settle.”
Leucovorin prescriptions rise by up to 113 percent
As well as the changes to Tylenol labeling, the Trump administration announced in that September briefing that it was initiating the approval process for a new use for a drug called leucovorin.
This drug is mainly used to counteract harmful effects that can occur when patients are given another drug called methotrexate, which is commonly used in the treatment of inflammatory disorders and cancer.
The Department of Health and Human Services, headed by Robert F. Kennedy, Jr., said that there was “promising” evidence that leucovorin could help with speech difficulties in a subset of autistic kids, which they blame on a deficiency of the mineral folate within the brain.
Again, when all this came out last September, experts said the evidence was nowhere near sufficient to make such a recommendation.
In this new study, as well as looking at Tylenol prescriptions, the team looked at prescriptions for leucovorin for children. New prescriptions for kids aged 5-17 increased by 71 percent during the study period. In the second week after Trump’s press briefing, prescribing went up by a whopping 113 percent.
“An important implication of these results is also that it’s not just patients who were influenced by the unconventional press conference. Their doctors were either influenced themselves or pushed by patients to adopt a new practice,” commented study author Dr Michael Barnett of Brown University in a statement.
The news about leucovorin is especially troubling in light of a recent report by The Transmitter’s Claudia López Lloreda, revealing that the largest study of the drug in autistic people has been retracted. The paper, which was published in the European Journal of Pediatrics in September 2024, now carries a retraction note detailing errors in the results and concerns around the statistical analysis, which ultimately mean the conclusions of the paper are no longer supported.
As The Transmitter article reports, there were only five randomized controlled trials of the drug in autistic people anyway, so losing one of them is a massive blow to its proponents.
The rapid spread of misinformation
There’s no way to prove for certain that these changes happened as a direct result of the Trump Administration. But both of these case studies could be taken as a warning about the potential risks associated with the rapid dissemination of misinformation in our hyperconnected world.
“It can take years, even decades, for high-quality research to finally reach clinicians. Here, by using the White House, it was done overnight,” said study author Dr Jeremy Samuel Faust of Harvard Medical School. “Unfortunately, they're claiming breakthroughs that simply haven't occurred.”
The changes in prescribing behavior for both Tylenol and leucovorin happened way before either the Tylenol meta-analysis or the leucovorin study retraction were published. But even before that meta-analysis, scores of experts were telling the world that Tylenol was safe. And even before that retraction, they were shouting that the evidence base for leucovorin was sketchy.
Unfortunately, all of those scientific experts were swimming uphill from the moment the President of the United States proclaimed a simple, three-word message in a press conference.
As Dr Barnett concluded, “The results show just how much political leaders can steer health behavior even when there has been no change in the evidence for these therapies.”
The study is published in The Lancet.
