Chuck Wiki

Riordan Payne holding the green antidote on the left and the red poison on the right.

In Chuck Versus the Truth, a toxic truth serum, described as a derivative of Pentothal, is featured. It is used by professional poisoner, Riordan Payne, at the beginning of the episode to extract information from Mason Whitney relating to nuclear missile codes. The poison forces the subject to tell the truth, which segues into manic behavior, followed by death, unless an antidote is administered.

During the course of the episode, Chuck, Sarah, Casey, Riordan, and Ellie are all poisoned with the serum. Ellie was the worst effected, lapsing into a coma, and coming close to dying from its effects, before Chuck administered the antidote to her.

The serum is red in color, with the antidote a bright green.