Selsun is a dedicated professional line of Dandruff Treatment Shampoo that helps to address severe dandruff problems. Powered by Selenium Sulfide; Selsun works by acting against the fungi Malassezia which is often the root cause of dandruff through its superior technology and constant innovation. Product efficacy and quality is of the core importance to us as Selsun aims to be the ultimate solution for Dandruff problems. When nothing else works, use Selsun!