Aging is mostly due to DNA damage, of which there are many many sorts. You need to have a cell dedicated to DNA repair and damage prevention at the molecular level, which would very likely result in macro changes such as slow movement and simplification of digestion. Nature provides examples of this, see the Greenland shark or the various giant tortoise.
>fisetin
no single supplement or small molecule is going to cut it. You need totally new enzymes and other repair systems running around the nucleus