Nioxin Scalp + Hair Thickening System 4 Leave-On Treatment is a lightweight, leave-in formula specifically developed to help strengthen and boost the appearance of thinning hair, especially for those with color-treated or chemically processed strands. Expertly crafted to support the needs of dry, damaged hair, this treatment enhances volume and body while nourishing the scalp environment. It works by fortifying each strand at the root to reduce breakage and improve density, leaving hair looking fuller, thicker, and more resilient with daily use. Ideal as the final step in the System 4 regimen, it absorbs quickly without leaving buildup or residue.
