Kérastase Serum Extentioniste 50mlDescription How to Use Ingredients Serum Extentioniste 50ml is a highly concentrated serum with key active ingredients that stimulate the growth of strong healthy hair follicles. This energizing leave in treatment is a key step to reinforce roots and promote a healthy scalp environment. Its non greasy formula harnesses the power of Ceramides to protect the scalp from environmental aggressors while stimulating and energizing roots. Applied with a