Collagen is a resistant and elastic protein that is widely distributed in the dermis (the deepest layer of the skin) to provide support. Collagen gives the skin elasticity, keeping it firm and compact. The reason for this is that it is found in the extracellular matrix of the dermis, which is an intricate network of molecules responsible for the "physical" structure of the skin itself. Thus, collagen cements the cells of the skin tissues and also contributes to their constant renewal.