Tylenol is the brand name of paracetamol, also known as acetaminophen, a widely used over-the-counter pain reliever manufactured by McNeil Consumer Healthcare, a Johnson & Johnson subsidiary. For decades, Tylenol has been marketed as a safe and effective treatment for mild to moderate pain and has even been deemed appropriate for use among pregnant women who may encounter frequent headaches, back pain, or other types of pain. As a group of leading scientists, medical experts, and public health professionals noted in a 2021 consensus statement published in the journal Nature Reviews Endocrinology, “APAP is widely used by pregnant women, as the FDA and EMA have long considered APAP-containing products to be of minimal risk when used as directed during pregnancy.” In addition to Tylenol, acetaminophen can be found in more than 600 other prescription and over-the-counter cough, cold, and flu medications, including Excedrin, NyQuil, Benadryl, and Robitussin.

Acetaminophen Linked to Autism, ADHD

Although federal regulators still recommend Tylenol as a medication that is generally safe to take while pregnant, studies published over the past several years have raised important questions about the actual safety of Tylenol use in pregnancy. As the authors of that same consensus statement warned in 2021, “increasing experimental and epidemiological research suggests that prenatal exposure to APAP might alter fetal development, which could increase the risks of some neurodevelopmental, reproductive and urogenital disorders.” Among these disorders are autism and ADHD, both of which are on the rise in the United States. Between 2009 and 2017, about one in six children aged 3-17 was diagnosed with a developmental disability, according to the U.S. National Health Interview Survey, an annual study of the health of the U.S. population. “Based on this research, we believe we know enough to be concerned about the potential developmental risks associated with prenatal APAP exposure and therefore call for precautionary action.” 

The doctors and scientists behind the 2021 consensus study have a great deal of research to support their call for “precautionary action,” including a 2021 study of prenatal and postnatal exposure to acetaminophen in relation to autism and ADHD symptoms developing in childhood. According to the study authors, children with prenatal exposure to Tylenol had a 19% increased risk of developing autism and a 21% increased risk of developing ADHD, compared to non-exposed children. In a 2019 study funded by the National Institutes of Health and conducted by Johns Hopkins University Bloomberg School of Public Health, researchers looked at samples of umbilical cord blood from 996 live births. They found that the group with the highest acetaminophen exposure had about three times the risk of developing ASD or ADHD by the time they were around eight or nine years old, compared to the group with the lowest exposure.