Matrix Full Densityhair thickening shampoo works on the surface of each strand to expand its diameter, leaving hair feeling thicker while reducing breakage. Formulated with a blend of Biotin, Zinc PCA & Gluco-Omega results in fuller-looking, thicker-feeling hair. Directions: Apply to wet hair with a massaging motion. Lather. Rinse. Follow with Full DensityConditioner. For maximum results, use the Full DensitySpray Treatment to instantly work on the surface of existing strands and expand the hair diameter. Hair feels thicker. Breakage reduced. Fortifies and removes follicle-clogging impurities.