Selenium sulfide is a chemical compound commonly used in medicinal shampoos and lotions to treat skin conditions like dandruff and seborrheic dermatitis. It works by reducing the growth of fungi and yeast on the skin, helping to alleviate itching and flaking. This compound is typically available in over-the-counter products and is applied directly to the affected areas. Users are advised to follow the instructions carefully to avoid potential side effects, such as skin irritation or discoloration. Regular use can lead to improved scalp and skin health.