If "poison" refers to a substance that causes harm:
* Antitoxin: A substance that counteracts the effects of a poison.
* Antidote: A remedy to counteract the effects of a poison.
* Cure: Something that heals or remedies a disease or condition caused by a poison.
* Remedy: A medicine or treatment for a poison.
* Treatment: Medical care given to someone who has been poisoned.
* Neutralizer: Something that eliminates the harmful effects of a poison.
If "poison" refers to something that is harmful or damaging:
* Benefit: Something that is advantageous or helpful.
* Advantage: A condition that gives someone a greater chance of success.
* Health: A state of well-being.
* Nourishment: Food or drink that provides sustenance.
* Good: Something that is morally right or beneficial.
If "poison" refers to something that is malicious or hurtful:
* Kindness: The quality of being friendly, generous, and considerate.
* Love: A strong feeling of affection and care for someone.
* Support: Help or encouragement.
* Compassion: Sympathy and concern for others.
* Harmony: A state of peace and agreement.
The best antonym for "poison" will depend on the specific context in which the word is used.