An ex vivo comparison of the tensile strengthening properties of protein derivatives on damaged hair

This study aims to compare the effects of three protein-derived conditioning actives (keratin, wheat and collagen hydrolyzates) on the tensile strength of three types of damaged hair: bleached, permed and thermally styled. The investigated actives were hydrolyzed keratin (600Da), hydrolyzed wheat protein (and) wheat starch (1,500Da) and hydrolyzed collagen (9,000Da.Hydrolyzed keratin was shown to improve the wet tensile strengths of all three types of damaged hair, thus emerging as the most efficacious treatment for wet hair, followed by hydrolyzed collagen. Hydrolyzed wheat protein and wheat starch was shown to be most effective in improving the tensile strength of dry hair, especially if bleached or thermally treated.