Collagen injections have been around for a while, but have decreased in popularity with the introduction of newer soft tissue fillers such as the HAs which last longer and do not requires skin testing.

    Collagen is the main protein found in connective tissue. It supports the skin, bone, cartilage and blood vessels. Collagen composes up to 80 percent of the skin. Its role is to maintain the skin's integrity, but collagen breaks down with advancing age.
    This breakdown can lead to wrinkles, lines and folds. Several types of collagen fillers are on the market. For example, collagen fillers containing human collagen include CosmoDerm and Cosmoplast (FDA approved 3/2003). Cow (bovine) collagen fillers
    include Zyderm and Zyplast (FDA approved 1981/1985). The results are immediate and become fully evident within one week. Results may be unpredictable, lasting from two to three months.