From BBC History- Training SOE Saboteurs in World War II:
... the 'L' tablet, which came in a little rubber cover, was a suicide
If the agent bit down on it, he would be dead in 15 seconds.
An L-pill is a lethal pill carried by spies to prevent them from
revealing secrets if captured and tortured.
During World War II, some
L-pills contained a lethal dose of cyanide encased in a glass capsule
that could be concealed in a fake tooth and released by the agent's
If he bit into the capsule and broke the glass, he would die
But if the pill came loose and was swallowed
accidentally while the agent was sleeping or chewing gum, it would
pass through his system without causing any harm, as long as it didn't
break and release the poison.
From the BBC documentary Hiroshima: Dropping the bomb:
The mission was so secret, Tibbets [the pilot of the Enola Gay ] was given suicide pills, in case
they fell into Japanese hands.
"That evening, when I came out the mess
hall, the Flight Surgeon gave me the pills. He told me what they were.
I hope you don't need them, but, he said, if you do, they're cyanide.
said, here, if you need them, one for each man of the crew. He said,
you'll never know anything, within six minutes, you're gone. You never
feel anything different, you never feel a thing.
And I told the guys
outside the airplane, before we climbed up, I'll give any one of you
the pill, if you want the pill. And no one said anything, but Captain
Parsons, he said, I'd like to have one. And I understood his position,
because he knew more technical stuff about that bomb than anybody."
From the New York Times (1987):
A man and woman who had been passengers aboard a South Korean jetliner
before it left the Middle East and disappeared over Burma took suicide
pills today as they waited for the police to question them, the
The man died, but the woman was expected to live.
The plane, with 115 people aboard, vanished near the Burma-Thailand
border, before a scheduled refueling stop in Bangkok. Officials in
Seoul have said there are strong suspicions that a bomb destroyed the
aircraft. Boarded at Baghdad
The man [...] died four hours after biting into a suicide pill concealed in a cigarette.
There is a belief that NASA gives out suicide pills to astronauts.
To quote Apollo 13's Jim Lovell:
Since Apollo 13 many people have asked me, "Did you have suicide pills
on board?" We didn't, and I never heard of such a thing in the eleven
years I spent as an astronaut and NASA executive.