- For methods of prolonging life that do not include actual rejuvenation, see life span.
Rejuvenation was a term referring to any process process which reversed biological aging. There were several documented 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)