People have tried in the past and each time it got thrown out because the judges ruled they were full of shit. As recently as 2023, even, from Reuters:

Cote, in a 148-page ruling, found that none of the five expert witnesses proposed by the plaintiffs had offered a sound scientific methodology to support their opinion that Tylenol's active ingredient, acetaminophen, could cause autism spectrum disorder (ASD) and attention deficit hyperactivity disorder (ADHD).

"Instead, the unstructured approach adopted by the plaintiffs' experts permitted cherry-picking, allowed a results-driven analysis, and obscured the complexities, inconsistencies, and weaknesses in the underlying data," she wrote.