SureThik high performance hair fibers are made of pure, natural keratin protein that has been precision cut into tiny micro-sized fibers. Keratin is the same protein found in your own naturally growing hair making our fibers virtually undetectable in comparison to other synthetic or cotton-based fibers. Our lightweight hair thickening fibers build upon your existing hair and naturally blend in seamlessly. SureThik fibers look, feel and style just like your own hair.