truth serum

American  

[trooth seer-uhm] / ˈtruθ ˌsɪər əm /

Often truth drug

noun

1. a drug, as the barbiturate thiopental, that induces in the subject a desire to talk or a state of heightened suggestibility, used in psychotherapy and in interrogation to discover repressed or consciously withheld information.

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Etymology

Origin of truth serum

First recorded in 1920–25

Example Sentences

As the YouTube hit demonstrates, hot sauce isn’t just for daredevils and masochists: It’s a truth serum.

From The Wall Street Journal • Nov. 20, 2025

“If opening day was today, he would certainly be running out there in center, which I know he loves. I think if you put truth serum in him, that’s what he’d want to do, regardless.”

From Seattle Times • Dec. 7, 2023

The Yes Men refer to their practice as “identity correction,” ventriloquizing what corporate culture would say if a truth serum made it display its real self.

From New York Times • Feb. 17, 2022

“COVID,” he says, “is a truth serum bringing it all out.”

From Los Angeles Times • Aug. 27, 2020

They’re trying to develop a powerful truth serum, one that even GPs as serum-resistant as I am are not immune to.

From "Allegiant" by Veronica Roth