- For methods of prolonging life that do not include actual rejuvenation, see life span.
Rejuvenation is the process where biological aging is reversed. There have been several natural, medical, and technological methods by which rejuvenation could be accidentally or purposely achieved.
Metaphasic radiation was found to actually rejuvenate individuals exposed to it, and it was thought that it could be developed into a treatment that could double the life span of Federation citizens. (Star Trek: Insurrection)