Nioxin SYS4 Scalp & Hair Treatment for Colored Hair with Progressed Thinning -  refresh the scalp and increase your hair volume. This volumizing leave-on treatment foam helps to provide thicker-looking hair by increasing the fullness of each hair strand. Nioxin’s Scalp & Hair Treatment is the final step of the 3-part System, which amplifies hair texture while protecting against breakage.Nioxin is the N°1 Salon Brand for thicker and fuller hair with more than 30 years expertise in thinning hair.