The basics Original Pro-Vitamin Leave-In Hair Treatment infuses hair with a Pro-B5 Vitamin formula to deeply penetrate and repair the hair cuticle layers. The benefits Improves manageability of hair for better styling and increased shine, while also detangling and strengthening to protect against breakage. The uses Can be used immediately following chemical processing to help seal the cuticle, protecting against split ends and breakage. The bottom line Pro-Vitamin Leave-In Treatment formula is lightweight, so it won't weigh hair down.