Sulfates are required in this product as a one-time pre-treatment step to open the hair cuticle so that it accepts the Gussi treatment, allowing it to truly penetrate the hair shaft. Gussi’s SqueakyClean Priming Shampoo has been designed with a neutral pH level equal to water and slightly higher than that of hair, making it far less damaging than other similar priming shampoos. Our Protection Plan Upkeep Shampoo and Conditioner that we recommend for ongoing use are both entirely free of sulfates.