System 1 Treatment is designed for natural, untreated hair with light thinning. Clinically and dermatologically tested, this nourishing and protective leave on treatment strengthens each strand from within, resulting in thicker, fuller hair. Nioxin Leave-In Treatment enhances the thickness and fullness of your natural hair. The lightweight formula adds body to your hair, making it look thicker and fuller. Formulated with a powerful blend of niacinamide, wild mint oil and caffeine to help nourish the hair root, stimulate hair follicles and strengthen the hair. THICKENS THE HAIR: clinically designed to add thickness and fullness to natural hair with light thinning, with visible results in just 30 days. SUPPORTS SCALP HEALTH: advanced formula gently cleanses the scalp, removing impurities and excess sebum that can clog hair follicles. REDUCES HAIR THINNING: helps minimize hair breakage, promoting the appearance of fuller, thicker hair. NOURISHES THE SCALP: Infused with antioxidants and UV protecting ingredients, this Treatment can nourish and revitalize the scalp, improving its overall health and condition.