Emollient

Hydroxystearic Acid

Also known as: octadecanoic acid, 12-hydroxystearic acid

May be derived from castor oil or created in a lab

What Is Hydroxystearic Acid?

Hydroxystearic acid is a fatty acid-based ingredient that has much versatility. It can work in cleansing formulas as a surfactant while adding emollient and texture-enhancing properties to products such as moisturizers, makeup, and sunscreens.\n\nThe natural form derived from castor oil is used most, but hydroxystearic acid can also be made synthetically. It is chemically similar to stearic acid, another fatty acid used in thousands of skin care, makeup, and hair care products since it is non-irritating and works well in many types of formulas.\n\nEmerging research from a supplier of an oleic acid-derived form of hydroxystearic acid shows it may play a role in reducing pore size and fading discolorations; however, independent research is needed to verify such claims.\n\nResearch from Unilever shows it works to help offset hyperpigmentation triggered by exposure to airborne pollutants, possibly due to its antioxidant ability which prevented the oxidation of lipids (fats) in skin that would normally occur when exposed to such pollutants.\n\nHydroxystearic acid is considered safe as used in cosmetics at concentrations of 10% or less. The typical usage level for this ingredient is 1-5%.

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