Free Fatty Acids

Free fatty acids — predominantly linoleic and palmitic acid in healthy skin — form the third pillar of the stratum corneum’s lamellar barrier alongside ceramides and cholesterol. They are critical for the acid mantle (skin pH ~5.5) and for the antimicrobial defence layer. Linoleate-linked ceramides specifically depend on sufficient fatty acid supply. In skincare, topical blends at 1–3% support barrier repair, replenish lipids lost through harsh cleansing, and calm tightness in dry skin. They are standard components of barrier creams and lamellar emulsions. Users battling over-exfoliation or winter dryness benefit most; pair with ceramide products for complete lamellar reconstruction.