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

“You can put me on the rack, the truth serum, whatever. I did not do it. … I did not shoot those people,” Titus said.

From Seattle Times • Jun. 1, 2023

Though occasionally used in court, forensic hypnosis was no truth serum.

From Los Angeles Times • Apr. 24, 2023

Give fans truth serum now, and they might be more concerned about whether the Commanders will sign wide receiver Terry McLaurin to a long-term deal than about Young’s progress.

From Washington Post • Jun. 2, 2022

The genetic anomaly that makes me aware during simulations also suggests I could be resistant to serums, so my truth serum testimony might not be reliable.

From "Allegiant" by Veronica Roth