I found this video on the website of GVI for their product FLEXHD. They made my testicle implants (which I like a lot). The video shows how a doctor is using it for girth enhancement. The sheet is made from donated human dermis.
Flex HD cellular dermis
www.gvi.com.mx/MTF/articulos/FLEX%20HD%20PLEGABLE/PLE%206.pdf
Acellular dermal allografts are donated human dermis that
has been processed to remove the components that could
result in any immune/inflammatory response and trigger
rejection. What remains is an undamaged tissue matrix,
capable of natural, full regeneration after implant.