Strengthen and protect strands with the Kérastase Resistance Serum Extentioniste, a nourishing leave-in hair serum that helps to protect against breakage. The non-greasy formula uses a host of powerful ceramides to seal the hair cuticle whilst a blend of lipids creates a smooth surface, creating a fortifying effect from the inside out.The highly concentrated serum forms a defensive barrier over the scalp to protect against damaging environmental aggressors, whilst also sweeping away impurities for a fresh appearance. Hair will be boosted, revitalised and given improved resistance. Scalp and hair Kérastase Résistance Sérum Extentioniste for hair seeking healthy length. Strengthens and fortifies hair for reduced breakage. Promote longer, stronger hair with the Kérastase Extentioniste Regime. This innovative range is designed to nourish and condition the hair to allow healthy growth, while minimising the appearance of damage and split ends for a salon finish. The luxurious, professional-quality formulas are infused with Creating, to leave your hair feeling smooth and sleek with a touchable softness.