The main sources for Keratin and Hydrolyzed Keratin are sheep wool and bovine hoof or horn. Goat wool, bird feathers, and human hair may also be used. Hydrolyzed Keratin is put through a hydrolysate process which makes the keratin stronger. Hydrolyzed Keratin also does not penetrate the hair shaft. It acts as a film-forming ingredient, creating a protective coating on the hair. This also helps to increase the shininess of the hair. When hydrolyzed keratin is used topically on the hair, it helps fill the minor gaps throughout the hair shaft, including its three layers known as the cuticle, cortex, and medulla. Filling these microscopic gaps with broken-down protein helps to strengthen hair's structure, thereby improving its overall elasticity.Hydrolyzed keratin minimizes the damaging effects of sun exposure, heat styling, chemical treatments, and combing hair—tangled tresses, especially.Studies show that hydrolyzed keratin can improve hair's texture so that it looks and feels smoother.1 In other words, it's a frizz-fighting machine.It also helps to rebuild the natural protective layer of hair from the inside by replacing lost protein and increasing each strand’s diameter, which gives it a fuller appearance