Nioxin system 4 cleanser shampoo 33.8 ounce liter delivers denser-looking hair and restores moisture balance system 4 is specially designed for noticeably thinning fine chemically-treated hair. It delivers denser-looking hair while protecting the scalp and providing moisture balance to colored hair. Helps to remove follicle-clogging sebum fatty acids and environmental residues from the scalp skin and hair. Cleanses to provide thicker-looking hair