Poison

Poisons, toxins, and venoms are all poisonous, intoxicating substances - powders, liquids, and gases - that can be used by ninja in combat. Poisons come with a variety of effects, ranging from body weakness, paralysis, or death.  Tsunade has been noted by Jiraiya to be the only person capable of poisoning a ninja without them knowing, as she managed to spike his sake with an odourless, colourless poison that left him unable to properly control his chakra.

Kabuto Yakushi has developed a poison which is specifically designed to suppress the Wood Release kekkei genkai. Sasori had developed such a poison that even if a small amount is introduced into the bloodstream, the affected person will die within three days while also being painfully paralysed for the duration. According to Sakura, this poison is refined with heavy metals which gets into the muscles and destroys the cells. The antidote for this poison is extremely complex so much so that no one in Sunagakure was capable of creating it. Orochimaru's true form's blood is poisonous, and evaporates upon contact with air, paralysing anyone who breathes it in. Its potency is such that even Sasuke Uchiha, who has gained an immunity to most poison, was affected. One of the poisons taught to Sakura by Shizune is able to be entrenched in kunai and has a delayed effect, as Naruto was cut with it but collapsed some time afterwards. Sakura also uses smoke bombs that contain a strong knock-out gas that can even render ninja like Sai, Lee, and Kiba unconscious in moments. Hanzō, in his youth, transplanted the poison sac of a black salamander in his village. He was able to poison the environment just from breathing. He also imbued his kusarigama's blade with poison. Ino Yamanaka has been shown to at least have knowledge of poisonous plants seen early when she threw poisonous plants into Ami's mouth.

She also makes heavy use of wolf's bane in the video games. Most poison users use poison on their weapons through various means. Sakura, for example, after learning from Shizune coats her kunai with poison so that if she is able to cut the target, they are instantly injected with the toxic substance. Puppet-users, such as Kankurō and Sasori, prefer to put poison inside their puppets so that they inject via hidden bladed weapons. Sasori, similarly to Sakura, puts poison that is clearly noticeable on the blades of his puppet, the Third Kazekage, as well as in his Iron Sand, which is far less noticeable. Poison may be used in other forms, not only as a liquid substance. It can be used in a mist form, as demonstrated by Shizune, with her Poison Mist technique. Inhaling the slightest bit of poison can prove fatal, as seen when Sasori trapped Sakura in two consecutive waves of his poison mist. Such vapours can also be used for paralysing effects, as Ibuse demonstrated. Certain characters have encountered poisons throughout their careers as ninja. Those skilled in the fields of chemistry and biology are capable of producing antidotes to the poisons. Tsunade, during the Second Shinobi World War, was able to produce antidotes to every one of Chiyo's poisons, much to the latter's resentment. During the mission to rescue Gaara, Sakura Haruno demonstrated the skill to not only extract and analyse Sasori's poison swiftly, but also produced an antidote to counter it, something Chiyo could not do. Apart from using antidotes to poisons, a ninja can also work to build-up a tolerance to certain poisons by gradually exposing oneself to non-lethal amounts of those poisons. Orochimaru, in the effort to make Sasuke Uchiha into the perfect vessel for his Living Corpse Reincarnation technique, made it a point to make Sasuke immune to most poisons, such as the one that Shizune taught to Sakura Haruno in order to use on her kunai. Anko was seemingly put under the same regime during her time with Orochimaru. Mifune has been shown to have built up an immunity to both Hanzō and Ibuse's poison.