Kérastase is taking a cue from skincare serums with its new INITIALISTE Scalp and Hair Concentrate. This new formula transforms hair in one week using Kérastase's SP94; an exclusive molecule with ingredients that come from plant biotechnologyexclusively patented by La Recherche Avancée L’Oréal. Engineered like a skincare emulsion, INITIALISTE features a Replenishing Complex to increase the hair fiber’s resilience and elasticity. The Replenishing Complex includes ceramides to reduce breakage by strengthening the hair fiber, conditioning agents to nourish the hair, and Green Tea Extract to give antioxidant protection. Even more than the ingredients, the whole process feels like that of a skincare serum with its lightweight, non-sticky formula that absorbs right into the hair. It's so lightweight, in fact, that you can (and should) use it on the roots of the hair, as well as the lengths.