La Roche-Posay Effaclar Purifying Clay Mask is a clinically proven treatment for oily, spot-prone skin. It has been shown to unclog pores, control shine, and cleanse deep impurities caused by pollution without over-drying the skin. 9 out of 10 dermatologists recommend La Roche-Posay Effaclar for oily, spot-prone skin. This mask contains Argilla and Kaolin, which work together to gently absorb sebum from the skin's surface and deep inside the skin. Argilla helps to control sebum production without causing micro-inflammation, while Kaolin helps to remove sebum and mattify the skin over time. The mask also contains 5% Panthenol B5 to soothe and calm the skin after sebum extraction, reducing the risk of over-stimulating the sebum glands. Additionally, the Cell beads provide an in-depth cleansing action by removing all impurities from the skin, including those caused by pollution.