Oleic acid is a monounsaturated fatty acid naturally found in many plant oils, such as olive, avocado and almond oil. In cosmetics, it is known for its ability to deeply nourish and soften the skin, making it more elastic and smooth. Oleic acid also helps restore the skin’s lipid barrier, making it especially suitable for dry and mature skin that lacks moisture and protection. In addition, it aids active ingredients in penetrating deeper layers of the skin, which is why it is often used in formulations of creams, lotions and serums.