Oleic Acid
Oleic acid is a monounsaturated omega-9 fatty acid (one cis-9 double bond) naturally found in many plant oils, including olive, avocado, macadamia, and marula oils. Its monounsaturated structure makes it thicker and heavier than polyunsaturated fatty acids. In its free form it primarily functions as an emulsifier or emulsion stabilizer in cosmetic formulations, and is also researched as a penetration enhancer in the pharmaceutical industry.
OA-rich oils are considered nourishing and moisturizing, making them generally more suitable for dry and mature skin types. Oleic acid has been studied for its role in skin penetration enhancement and wound healing immune modulation. Its emollient properties help soften and condition the skin.
Oleic acid is considered comedogenic; individuals with acne-prone skin are advised to avoid oleic acid-rich plant oils and opt for linoleic acid-rich alternatives instead. Peroxidized forms (e.g., from squalene and oleic acid peroxides) have been linked to enhanced comedo formation.
