The sun, saltwater, and chlorine can dry out and dehydrate our hair. In these cases, keratin, the main ingredient, is particularly indicated. It acts to reconstruct the weak shaft, which has indeed lost its natural keratin content and needs external help. The keratin contained in the products blends with the naturally occurring keratin to fill the fibers and give the hair a healthier appearance. On damp or dry hair, apply to the lengths. It absorbs quickly, is non-greasy, does not weigh down, and leaves no residue. No rinsing required.