“I think science ought to guide these discussions and our decision-making around our health,” Thune said, telling CNN he was “obviously very concerned” about Trump’s comments and how they might affect the health of pregnant women.

“There are studies out there that they reference, but again I think there are an awful lot of people who come to a different conclusion about the use of Tylenol,” the Senate majority leader said when asked about Trump on Monday urging pregnant women not to take Tylenol, alleging that its main ingredient, acetaminophen, is linked to autism.

Thune is the highest ranking Republican to publicly question Trump—Sen. Bill Cassidy, R-La., a medical doctor who has been one of the most outspoken Republican critics of Health and Human Services Secretary Robert F. Kennedy Jr., has also disputed Trump’s remarks linking autism and the use of Tylenol while pregnant.

Cassidy urged HHS to “release the new data that it has to support this claim,” writing Monday on X “the preponderance of evidence shows that this is not the case.”