Stearic Acid

Emollient that softens and smooths the skin. Stearic acid, a saturated fatty acid naturally present in skin lipids, primarily functions as an emollient and occlusive agent by forming a protective film on the skin's surface. This film helps to reduce transepidermal water loss (TEWL), thereby improving skin hydration, softness, and suppleness. It reinforces the integrity of the stratum corneum lipid barrier, contributing to enhanced skin barrier function. In formulations, it also acts as an emulsifier, opacifier, and viscosity increasing agent.

Stearic acid is generally considered safe for use in cosmetics. The Cosmetic Ingredient Review (CIR) Expert Panel concluded that stearic acid is safe as a cosmetic ingredient. It is largely non-irritating and non-sensitizing.

Look for products with 1-25% (most formulas use 2-10% for emulsification and thickening, but it can be used at higher concentrations for solid or semi-solid formulations like stick products). for clinical efficacy.