Hydrolyzed algin is a hydrolysate of algin, a polysaccharide obtained from brown seaweeds. In cosmetics and personal care products, hydrolyzed algin functions as a humectant moisturizer and skin-conditioning agent. A humectant is a hygroscopic substance that has a molecular structure with several hydrophilic (water loving) groups. This structure allows humectants to attract and retain the moisture in the air nearby via absorption, drawing the water vapor into or beneath the surface. Humectants improve moisture retention, which is why hydrolyzed algin is often used in creams, lotions, and other types of moisturizers. Additionally, hydrolyzed algin may be combined with zinc sulfate for the treatment of acne. It is thought that this combination can help control sebum levels, inhibit acne bacteria, and reduce irritation.