Bosley BosVolumize Hair Thickening Fibers Dark Brown - 12g BosVolumize Hair Thickening Fibers naturally bond to existing hair with keratin fibers that blend and cover thinning and low density areas. Because our own hair is made of Keratin and naturally holds a positive charge, BosleyMD Hair Thickening Fibers are designed to mimic our own human hair but with a negative charge. Therefore, when negatively-charged, lightweight, easily blended BosleyMD Fibers come in contact with our positively-charged hair, it creates a static-cling effect, naturally binding to the hair shaft creating instantly thicker, fuller looking hair. Blend and cover thinning and low density areas with Keratin Hair Fibers that naturally bond to existing hair for instantly thicker, fuller-looking hair. Also great as a root touch up between color service. Use Style hair as usual. Liberally shake fibers into thinning areas and gently style into place with fingers or comb. Shampoo to remove. Tips: For added hold, spray BosleyMD Styling Hairspray after applying Hair Thickening Fibers. BosleyMD Hair Thickening Fibers also work great as a root touch-up in between color service.