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Biological additives are also found in cosmeceuticals and are derived from the extracts and hydrolysates of glands and tissues of animals of different species. Biologics can be obtained as aqueous, hydroglyceric, hydroalcoholic, hydroglycolic, and oily extracts of animal-derived products. Commonly used cosmeceutical biological additives include collagen, elastin, hyaluronic acid, keratin, placenta, blood derivatives, and stem cells.

Collagen, a large molecule composed of three twisted alpha helical peptide chains, is a biological additive used in some cosmeceutical moisturizers. Collagen is usually obtained from shredded calf skin that is carefully handled to eliminate denaturation.

Elastin, a structural component of the dermis responsible for the ability of the skin to regain its original configuration following stretching and other deformation, is obtained from bovine neck ligaments. Elastin, usually added as a hydrolysate, is a clear yellow liquid. While the addition of collagen and elastin to a cosmeceutical moisturizer might be presumed to thicken skin and increase elasticity, these ingredients actually function as humectants to improve the water-holding capacity of the skin [29]. Part of evaluating cosmeceutical efficacy is to determine the true value of a biologic additive.