Nexxus® Curl Define Moisturizing Shampoo Sulfate free for curly hair and coily hair has been specially formulated to help strengthen and moisturize curly hair. This curly hair shampoo works with the Curl Define system to restore strength from within. Created with our exclusive PROTEINFUSION blend with silk protein and marula oil, this curl enhancer shampoo with protein helps preserve and protect the essential proteins curly and coily hair needs. This shampoo for curly hair provides strength and moisture to curls and coils.