Cyanide Pills

A Cyanide Pill, also known as suicide pill, is a little capsule containing a poisonous substance designed to be ingested deliberately to quickly end his own life.

History
When S.H.I.E.L.D. agents Phil Coulson and Melinda May were trying to capture and interrogate former agent Richard Lumley in Mexico, and interrogate him about her partner agent Linda Avery, Lumley tried to consume one of these pills concealed in his watch before he was captured, fearing Coulson and May wanted to torture him, as he was shown to be very relieved when they identified themselves as Agents of S.H.I.E.L.D.