A decade of delay: Internal FDA reports reveal unheeded warnings on Tylenol and pregnancy risks

By willowt // 2025-10-22

Mastodon

Parler

Gab

Copy

The FDA ignored nearly a decade of internal expert advice to warn pregnant women about potential neurological risks to children from acetaminophen use.
Internal reports from 2016, 2019 and 2022, along with recommendations from agency divisions, consistently pointed to an association with conditions like autism and ADHD.
A key decision-making committee, led by a controversial official, repeatedly declined to act on these recommendations for public communication.
The agency only issued a new, nuanced warning in September 2025 after a change in presidential administration.
The delay occurred despite growing external scientific consensus and action by European regulators.

For nearly a decade, internal drug safety experts within the U.S. Food and Drug Administration (FDA) repeatedly advised the agency to warn pregnant women that taking acetaminophen, the active ingredient in Tylenol, might be linked to neurodevelopmental disorders in their children. According to internal documents obtained and published in October 2025, these experts produced multiple reports between 2016 and 2022 identifying a consistent association between prenatal acetaminophen exposure and an increased risk of autism spectrum disorder and attention-deficit/hyperactivity disorder. Despite this growing body of internal evidence and recommendations, FDA leadership declined to update public safety advice until September 2025, leaving millions of expectant mothers and their doctors without official federal guidance on the potential risks of one of the most commonly used medications in pregnancy.

Mounting evidence, stalled action

The FDA’s internal scrutiny of acetaminophen began over a decade ago. A 2014 study published in the Journal of the American Medical Association raised initial concerns, prompting the FDA to issue a brief statement in 2015 acknowledging it was "aware of concerns" but taking no further action. The internal momentum, however, was building. By October 2016, FDA Senior Medical Officer Dr. Andrew Mosholder had compiled a 22-page report reviewing eight observational studies. Seven of those studies found an association between the drug and issues including attention deficits, delayed motor development and autistic behaviors. Mosholder’s report recommended the FDA issue a nuanced public communication. He advised that acetaminophen use in pregnancy could cause neurological harm and should be used sparingly, while also acknowledging that other painkillers carry more definite risks and that Tylenol is sometimes necessary to reduce fever, which itself poses a danger to a fetus. This balanced approach was also supported by the FDA's own Division of Pediatric and Maternal Health and Division of Bone, Reproductive and Urologic Products in 2016 and 2017. The experts were not claiming definitive proof, but they argued it was "prudent" to inform the public of the potential risks identified in a growing number of peer-reviewed studies.

The committee that said "wait"

By early 2018, the internal evidence had expanded significantly. Mosholder and a colleague presented to a key FDA decision-making committee, showing that they had reviewed 21 studies, three-fourths of which indicated a risk from prenatal Tylenol exposure. The committee was headed by Dr. Janet Woodcock, the longtime director of the FDA’s Center for Drug Evaluation and Research. Woodcock’s tenure was marked by other controversial decisions, including the approval of OxyContin and the alleged suppression of a 2003 report by Mosholder linking antidepressants to increased suicide rates in children. The committee, however, did not endorse Mosholder’s recommended public statement. Instead, it postponed a decision for six months. When the group reconvened later in 2018, and even after the FDA’s own toxicology division shared a hypothesis that Tylenol could impede blood flow to a developing infant, no changes were made to the agency’s public advice. This internal stall continued despite the European Medicines Agency informing the FDA that it planned to issue a warning to patients. Mosholder’s subsequent epidemiological reviews in 2019 and 2022 continued to find associations—adding potential defects in the urinary and reproductive tracts to the list of concerns—and continued to recommend public communication. The FDA’s official position remained unchanged.

A sudden reversal after years of silence

The FDA’s public stance remained frozen for years, relying on its minimal 2015 statement even as external scientific consensus grew. Major studies, including those from the Boston Birth Cohort, and meta-analyses in journals like the European Journal of Epidemiology, consistently pointed to a 19-21 percent increased risk for autism and ADHD symptoms in children who were prenatally exposed. This left a significant gap between the scientific discourse and official federal guidance. The logjam broke abruptly in September 2025. Under the direction of a new presidential administration and Health and Human Services Secretary, the FDA finally issued the nuanced warning its experts had long advocated. The agency announced it was initiating a label change for acetaminophen products and notified physicians of the potential link. The press release carefully mirrored the balanced language Mosholder had proposed nearly a decade earlier, stating that while a "causal relationship" was not proven, a "considerable body of evidence" suggested an association. It reiterated that acetaminophen remains the only over-the-counter drug approved to treat fever during pregnancy and that high fevers themselves are dangerous.

A precaution foretold

The recently revealed internal documents tell a story of caution within the FDA’s own ranks that failed to translate into public-facing action for almost ten years. They reveal a bureaucracy that, despite consistent internal findings and recommendations from its scientific staff, hesitated to alter advice on a bedrock household medication. This delay highlights the complex challenges of regulating long-approved drugs in the face of emerging safety signals and raises profound questions about transparency and the pace of regulatory action. For the millions of women who used acetaminophen during their pregnancies between 2016 and 2025, the newly public internal warnings come as a retrospective revelation of a risk they were never officially told the FDA was actively considering. The agency’s eventual action, while welcomed by public health advocates, serves as a case study in how scientific prudence within a regulatory agency can be slow to reach the public it is meant to protect. Sources for this article include: TheNewAmerican.com DailyCaller.com FDA.gov