Are alloderm and cymetra permanent?

No. Alloderm and it's injectable form, cymetra, are acellular tissue "fillers" used surgically to bridge gaps such as hernias or reinforce weakened tissue. They are made from cadaveric human skin that has been specially treated to remove all but collagen matrix which is used as a lattice for the body to form scar tissue around. It is slowly reabsorbed in this process and gone within 6-12 months.