The invention relates to a method for reprogramming cells from aged donors or senescent cells to pluripotent cells that have lost marks of senescence. In particular, the invention relates to an ex vivo method for preparing induced pluripotent stem cells (iPSCs) from a target cell population comprising cells from aged donors or senescent cells, said method comprising the steps of culturing said target cell population under appropriate conditions for reprogramming said cells into iPSCs, wherein said appropriate conditions comprises increasing expression in said target cells, of at least the following reprogramming factors: Oct4, Klf4, Sox2, c-Myc, Lin28 and, optionally Nanog.