Linoleic Acid
Linoleic acid (LA) is a polyunsaturated omega-6 essential fatty acid with the INCI name 9,12-Octadecadienoic Acid (9Z,12Z), also known as a form of Vitamin F. It is the most abundant fatty acid in the epidermis and serves as a structural precursor for ceramides, playing a central role in stratum corneum permeability and skin barrier function. It is naturally found in nuts and vegetable oils such as sunflower and safflower oil, and cannot be synthesized by the human body. Its official CosIng functions include antistatic, cleansing, emollient, hair conditioning, skin conditioning, and surfactant.
Linoleic acid helps repair and maintain the skin's permeability barrier, making it beneficial for dry and barrier-damaged skin. Research indicates it can reduce acne microcomedones by approximately 25% (in a 2.5% LA gel over 4 weeks) and addresses the LA deficiency observed in acne-prone skin. It also lightens UVB-induced hyperpigmentation by inhibiting melanin production in melanocytes and enhancing desquamation of melanin pigment from the upper skin layers.
