most medical collagen is derived from young beef cattle (bovine)
from certified BSE (Bovine spongiform encephalopathy) free animals.
Most manufacturers use donor animals from either "closed herds", or
from countries which have never had a reported case of BSE such as
Australia and New Zealand.
porcine (pig) tissue is also widely used for producing collagen
sheet for a variety of surgical purposes.
alternatives using the patient's own fat, hyaluronic acid or
polyacrylamide gel are readily available.
