Bain de Terre Natural Texture Cysteine Perm Color-Treated or Previously Permed Hair Natural texture cysteine perm is ideal for color-treated hair. It is also great for previously permed hair. Natural texture cysteine perm features a low pH level and is free of thio and ammonia. The formula contains cysteine, a natural amino acid, which – due to its natural origins - provides the gentlest form of perming and acts as one of the most natural and safest reducing agents on the market. The advanced, patent-pending additive significantly reduces perm odor during and after processing as all-natural alfalfa extract provides additional proteins and vitamins to strengthen and moisturize the hair.