“Late Show” host Stephen Colbert said President Donald Trump this week held an “insane” press conference in which he linked autism to a drug he couldn’t even pronounce.

“Autism is a simple term that actually covers a variety of developmental differences across the spectrum and you can’t blame anyone, even Donald Trump, for seeking answers,” Colbert said on Tuesday.

Then his tone shifted ― fast.

“But experts in the field caution that what President Trump said in his speech yesterday was ― and I don’t want to get bogged down in technical jargon here ― ‘fucking crazy,’” Colbert said.

Trump said the pain reliever Tylenol (acetaminophen) can cause autism and warned women not to take it during pregnancy. Experts, as Colbert noted, slammed the claim as “irresponsible” and “highly unsettling.”

Colbert said Trump’s claim is based on a single paper that found a correlation between prenatal use of the drug and autism.

“But even the lead author of that study cautioned that correlation is not causation,” he pointed out. “For example, I picked a side salad over fries the day my show got canceled. Is that why? Probably not. But just to be safe, I will never eat a salad again.”

Colbert rolled footage of Trump’s word-salad press conference where he struggled to say “acetaminophen.”

“Is that OK?” Trump asked after several attempts.

“No,” Colbert fired back. “That’s not OK. Doesn’t exactly inspire confidence.”

See more in his Tuesday night monologue: