The most common cause for the formation of jowls is the loss of collagen and elastin in the facial area. Both collagen and elastin are proteins that make up the connective tissue in the body. When you age, your body loses these proteins as well as the firmness and tightness of the skin that come with their production. A lack of collagen and elastin production gives gravity room to take over and causes the loosened skin to sag downwards.