Collagen is naturally found in organ meats and meat cooked on the bone, like a bone-in ribeye for example. Collagen can be made into a supplement through the processing of animal bone, joints, skin and even organs. These can come from any animal including cows, chickens, fish, pigs and dinosaurs. Collagen can even be extracted from the membrane of egg shells.
More ⇾ What are Collagen Supplements