Collagen
Collagen is a naturally occurring protein that provides support to various parts of the human body: the skin, the joints, the bones and the ligaments. Injectable collagen, patented by the Collagen Corporation under the trade names Zyderm and Zyplast, is derived from purified bovine collagen.

Fat
In the medical world, the fat-injection procedure is known as autologous fat transplantation or microlipoinjection. It involves extracting fat cells from the patient's abdomen, thighs, buttocks or elsewhere and reinjecting them beneath the facial skin. Fat is most often used to fill in "sunken" cheeks or laugh lines between the nose and mouth, to correct skin depressions or indentations, to minimize forehead wrinkles and to enhance the lips.

Content courtesy of plasticsurgery.org