Regeneration Techniques

are ninjutsu that allows the user to heal their bodies from damage incurred. Depending on the strength of the techniques, some may be even powerful enough to purge the body of poison. Some regeneration techniques may be an application of medical ninjutsu onto the user's own bodies, while others may be gathering a huge amount of chakra to repair the body.

A potential drawback to regeneration techniques is that the body's cells are limited to how many times they can divide themselves in one's lifetime, and by accelerating that division to recreate lost limbs and organs, one is basically shortening their lifespan. Certain techniques of extreme destructive power, such as the True Fire of Samadhi and Destruction Beam are capable of overwhelming regeneration techniques.

Some regeneration techniques can be used to extend one's lifespan, but this cannot be indefinite, as it would eventually reach a limit, and the body would succumb to senescence.

The cells of Hashirama Senju possess an immense Regeneration Ability that requires no hand seals. Once Madara Uchiha acquired this power, along with becoming the Jinchūriki of the Ten-Tails, he elevated this regenerative power to the point of a form of "immortality", able to survive even from bisection at his waist.

Trivia

 * The Creation Rebirth was considered to be the "ultimate regeneration technique".
 * Victor was known for his skills in regeneration techniques, though in the anime, Orochimaru noted it was imperfect as he could not restore the leg and eye he lost years prior. Furthermore, having utilised a cursed seal to extend his own life, the prolonged usage of regeneration had accelerated his health decline, the reason he permanently lost his leg and eye.
 * Shinnō was noted to have invented many regeneration techniques, and having taught Orochimaru several of them. It was for this reason that Orochimaru desired to capture Shinnō, in hopes of extending his host's vitality.
 * In the anime, Mitsuki seems to possess a degree of regeneration. After losing an arm, he stated it would heal and will be fine. In the following episode, he has a new arm.