An antidote is a chemical or medicine that will reverse the effects of some poisons. An antidote will make some or all of the effects of the poison go away.

Each antidote only works for certain poisons.

Not every poison has an antidote. For example, the poison aconitine has no known antidote. Aconitine is a very poisonous toxin that comes from the Aconitum plant. If enough of the poison enters a person's body, the person often dies.