This medicated shampoo is specially formulated to offer relief from stubborn dandruff, and more serious scalp and skin conditions, like seborrhoea dermatitis. __Benefits:__ - Treats dandruff and the skin disorder, seborrheic dermatitis - Contains 2.5% Selenium Sulfide, a strong antifungal highly effective against dandruff - Regular dandruf shampoos usually contain only 1% Selenium Sulfide - Reduces greasiness on scalp - Inhibits the growth of skin cells that cause dandruff The active ingredient is Selenium Sulfide, of which there is 2.5%. Selsun anti-dandruff shampoo (Selsun Shampoo 2.5) is currently the only dandruff shampoo that contains 2.5% of the active ingredient. Other alternatives with Selenium Sulphide generally only contain around 1%. Selenium is a strong antifungal that is highly effective against dandruff. It\'s also a cytostatic agent, meaning it slows down the production of skin cells on the scalp that cause dandruff. Selenium Sulphide is considered so effective that it\'s also used to treat tinea versicolor, a condition that causes skin discolouration.