The formulation of Ducray Kelual DS Treatment Shampoo combines two complementing antimicrobial active ingredients: Cuclopiroxolamin and Purithione Zinc. It has been scientifically shown that yeasts (type malasseza) are the primary cause of dandruff. Ducray Kelual DS Treatment Shampoo also contains Keluamid, the unique exfoliating ingredient, which boosts anti-dandruff activity and sanitizes the hair scalp.