Pharmaceutical company Kenvue, the maker of Tylenol (known as paracetamol in the UK), has said its drug remains safe, after its shares fell sharply following a report that US Health Secretary Robert F. Kennedy Jr. may have linked the drug's use during pregnancy to autism.
According to the BBC, Kenvue shares fell 14% in trading on Friday, before recovering slightly, closing the day down 9.5%. The company has come out publicly to defend the drug's reputation, stressing that there is no scientific evidence to support such a link.
Reports from the Wall Street Journal suggest that Kennedy is expected to release an official report this month on the rise in autism cases in the US, which will cite Tylenol use during pregnancy as a possible factor. The Department of Health and Human Services has responded, saying that the information contained in the report is merely “speculative” and that the conclusions will be based on “gold standard science.”
American doctors typically recommend using Tylenol during pregnancy for pain and fever relief, avoiding ibuprofen, which is considered more dangerous for the mother and fetus. Kenvue stated that “there is no cause-and-effect relationship between acetaminophen use during pregnancy and autism” and that all major medical organizations consider its use safe when guidelines are followed.
The American College of Obstetricians and Gynecologists (ACOG) recommends that all pregnant women consult their doctor before using over-the-counter medications. “There is no clear evidence that shows a direct link between the prudent use of acetaminophen and fetal developmental problems,” said Christopher Zahn, chief of clinical practice at ACOG.
The scientific evidence on this issue remains inconclusive. An analysis by researchers at the Icahn School of Medicine and Harvard T.H. Chan School of Public Health of 46 previous studies showed mixed results: 27 suggested an increased risk of neurodevelopmental disorders, 9 found no link, and 4 reported protective effects. On the other hand, a 2024 study published in the Journal of the American Medical Association, which included 2.4 million children born in Sweden, found no evidence to support a cause-and-effect relationship.
Kenvue has been the subject of hundreds of lawsuits for years alleging that taking Tylenol during pregnancy causes autism. However, in August of last year, a federal judge dismissed all the cases, arguing that the plaintiffs had not presented sufficient scientific evidence. The ruling is now on appeal.
Autism, which affects communication skills and social behavior, affects one in 31 children in the U.S., according to the CDC. Scientists say the increase in cases is also related to greater awareness and a broadening of the definition of the disorder, but studies on environmental factors and the impact of medications continue.