Kenvue Inc (NYSE:KVUE) shares dropped 4% at the open on Monday, erasing about $1.4 billion in market value, after a report that Trump administration officials plan to warn pregnant women against taking Tylenol unless they have a fever.
The Washington Post said the guidance will claim the active ingredient, acetaminophen, is linked to autism, citing unnamed sources.
The news extends pressure on Kenvue, which has already seen its stock fall over 17% this year.
The company pushed back on the report, saying, “Independent, sound science shows taking acetaminophen does not cause autism.” It added that more than a decade of studies, backed by health regulators worldwide, had found “no credible evidence” of a connection.
Acetaminophen, known as paracetamol in Europe and much of the rest of the world, is one of the most widely used over-the-counter pain relievers globally.
Concerns about its use during pregnancy have surfaced before: in 2023, a US federal judge dismissed hundreds of lawsuits, ruling the evidence linking prenatal exposure to autism was unreliable.
A large Swedish study published last year also found no increased risk among nearly 2.5 million children.
The Post said the administration also plans to promote leucovorin, a generic cancer drug, as a possible autism treatment. President Trump has promised a major announcement on autism later Monday.