RFK Jr.’s planned report linking Tylenol to autism crashes shares of parent company Kenvue

What’s in the planned report

• Multiple outlets report that the forthcoming HHS autism report led by Robert F. Kennedy Jr. is expected to suggest that acetaminophen use in pregnancy is linked to autism and to highlight low folate levels, while pointing to folinic acid (leucovorin) as a potential way to reduce symptoms for some individuals with autism, according to people familiar with the draft cited by the Wall Street Journal, which was first to report the news.
• HHS has said conclusions should not be assumed until the final report is released, and Kenvue has stated it has continually reviewed the science and sees no causal link between acetaminophen use during pregnancy and autism.

Past claims about autism

• Fortune Well has contextualized RFK Jr.’s broader claims by reporting his focus on “environmental toxins” as key drivers of rising autism diagnoses, framing his assertions amid scientific uncertainty on specific non-genetic causes.
• Fortune Well also scrutinized RFK Jr.’s earlier “MAHA report,” reporting that it cited nonexistent or misinterpreted studies, signaling concerns about rigor and interpretation likely to shape reception of any new claims about acetaminophen.

What the science says

• A very large 2024 JAMA study of nearly 2.5 million Swedish children, using sibling-control analyses to account for familial confounding, found no association between prenatal acetaminophen exposure and diagnoses of autism, ADHD, or intellectual disability, a finding also summarized by NIH and advocacy groups.
• Conventional adjusted models often show small associations, but these are likely explained by unmeasured factors; in the JAMA study, the slight risk elevations disappeared in sibling analyses, while a prior meta-analysis without sibling controls reported ~19% higher odds for autism symptoms and ~21% for ADHD symptoms, illustrating how confounding can influence results.
• Major professional societies (ACOG and SMFM) continue to recommend acetaminophen as a first-line option for pain and fever in pregnancy when medically indicated, at the lowest effective dose for the shortest necessary time, and they do not advise changing practice based on current evidence.
• A 2021 “precautionary” consensus statement urged caution with acetaminophen in pregnancy, but ACOG and other groups responded that the evidence for causality is weak and does not justify altering clinical guidance, underscoring the difference between association signals and proof of cause.

Kenvue stock reaction

• Reports that RFK Jr.’s upcoming HHS document will tie Tylenol in pregnancy to autism triggered a sharp selloff in Kenvue shares, with coverage noting declines of more than 6% intraday and a notably severe session for the stock when it fell over 14% before paring losses.
• Additional outlets highlighted that Kenvue was among the market’s most active movers as the news spread, and global coverage described the company’s stock as “hit” following the report chatter.
• Recent trading data show wide intraday swings and heavy volume in the aftermath, with a day’s range that captured a deep drop and partial recovery, underscoring ongoing volatility rather than a settled trend.
• The planned report is expected to assert an acetaminophen–autism link, but the strongest recent evidence does not support causation, and leading medical bodies still endorse careful, indicated use of acetaminophen in pregnancy; Kenvue’s stock has been under pressure amid the headlines and remains volatile.

For this story, Fortune used generative AI to help with an initial draft. An editor verified the accuracy of the information before publishing.