Regenerative medicine is one of several different approaches to life extension and improved human longevity.
Cell therapy involves the adding of younger or progenitor cells, the removal of senescent or destructive cells, and the genetic reprogramming of cells in situ. New and reprogrammed cells then grow within the pre-existing matrix.
Tissue engineering involves the growth of tissues or entire organs within artificial scaffolding. This growth may occur outside the body (for later transplant) or inside the body with in situ tissue engineering.
Cell therapy is the easier approach, but may take several decades of development to achieve the regenerative power that tissue engineering promises to provide within one decade.
Hormonal and growth factor regenerative medicine use chemicals to alter the cells from the outside, in a therapeutic sequence. This approach is even easier than cell therapy, but is also more limited.
There are other regenerative therapies which work via the immune system, and via epigenetic systems, and some of these will come into use within the next decade or two.
Other life extension strategies -- such as cryonics, mitochondrial rejuvenation, technological prostheses, and the total redesign of the human body -- will continue to receive varying levels of support. One should also keep an eye on SENS .