The Idou Idou no Mi grants the user enhanced regeneration from minor wounds and a good majority of near-fatal ones. In addition to using the fruits skills to speed up the healing process of his own body, the user can also use it to heal the injuries of others. It also augments the users skills and abilities as both a Doctor and a Surgeon
Standard Devil Fruit weaknesses apply. In addition, the powers of the Idou Idou no Mi cannot make up for blood loss, nor can they heal a person after they've been either decapitated or dismembered in some manner.
By laying hands on either himself or another, Nadeisco can greatly speed up the body's natural healing process, recovering from wounds that would normally either incapacitate or kill in a matter of minutes.
Rejuvenation: This is a unique ability where Nadeisco can heal his wounds without making contact with himself. It seems to have a limit to how often he can use it, because he mentioned that he couldn't use it on Parm after using it on Hitoya. By that time span, it seems he cannot use it over the course of several days, possibly a week.