The Strengthening Bond Builder by KERASILK is a deep-acting, intensive treatment with Biomimetic Silk and Bondamide. Its 100% vegan formula builds new hair bonds to repair brittle, dull, rough, and even highly damaged hair. The Kerasilk Strengthening Bond Builder strengthens the hair structure down to the cortex and prevents future damage - for up to 20 x stronger hair, long-lasting stability, and up to 98% less hair breakage.