Powered by fermented black tea and glycolic acid, the Biolage Scalp Sync Oil-Balancing Serum is a lightweight, leave-in formula expertly formulated to help reduce excess oil and leave the scalp feeling refreshed. Applied on wash days, the silky formula supports a fresher feel for longer, ideal for those managing an oily scalp between washes. Used alongside the Scalp Sync routine, the serum helps to visibly refine the scalp’s surface, leaving hair looking cleaner and lighter.