Zero Frizz 10 Real Benefits Keratin Leave-In is a lightweight leave-in treatment designed to nourish, protect, and strengthen hair while making daily styling easier. Enriched with keratin, it helps repair the appearance of damaged hair, smooth frizz, and leave hair soft, shiny, and manageable without weighing it down. Suitable for all hair types, especially dry, frizzy, chemically treated, or damaged hair. Keratin leave-in products are commonly used to help strengthen hair, reduce frizz, improve shine, and provide heat protection.