Ricin.
It's an extremely EFFECTIVE poison.
Breaking Bad Season 2, Episode 1
...which are only EFFECTIVE against
wraiths and daywalkers...
The Big Bang Theory Season 3, Episode 5
It's really EFFECTIVE.
Westworld Season 2, Episode 6
SHELDON:
It was obviously EFFECTIVE.
The Big Bang Theory Season 1, Episode 16
Placinex proved
extremely EFFECTIVE in treating
The Big Bang Theory Season 9, Episode 12