Eicosapentaenoic Acid

Eicosapentaenoic acid (EPA) is an omega-3 fatty acid used topically mainly for barrier support and anti-inflammatory benefits, typically at low concentrations (often ~0.1–2%) in lipid-based formulas. As a non-acidic, skin-identical lipid, it is generally very well tolerated with low irritancy in patch-testing experience, though rare sensitivity can occur (more often due to oxidation byproducts or the overall formula). Given the low inherent irritancy of fatty acids but acknowledging compromised-skin populations and oxidation risk, a very gentle score is most consistent with patient safety. Safety Notes: In commercial skincare, EPA is most often delivered via marine/algae lipid blends where the finished-product EPA content can be extremely low (trace-level labeling use around ~0.001–0.05% EPA equivalent) in leave-on creams/serums and occasional rinse-off cleansers. Higher-strength consumer products (typically leave-on anti-inflammatory/acne/rosacea-leaning serums or oils using concentrated algae/fish-oil EPA fractions) reach about 1–5% EPA, with ~5% representing the upper end observed due to odor, oxidation/stability constraints, and sensory limits; higher levels are uncommon outside professional or prescription contexts.