Actives glossary
Free fatty acids
The third barrier lipid class, usually delivered through plant oils rather than named directly.
- INCI name
- Linoleic Acid, Oleic Acid, Stearic Acid
- Also called
- FFA, barrier lipids
- Family
- Lipid
- Range seen on labels
- Rarely published
- Sits well with
- ceramides, cholesterol
- Needs care with
- No common conflict note
Free fatty acids complete the three-part barrier lipid mixture. On an INCI list they often arrive inside a plant oil rather than under their own names: sunflower oil is largely linoleic acid, shea butter carries stearic and oleic, and tamanu oil is a mix.
The consequence for reading a label
A cream can contain a substantial fatty acid fraction without ever printing the words. This makes the barrier category harder to score than the retinoid one, where the active is named. It is also why our barrier ranking scores whether a brand names all three lipid classes as a disclosure question rather than as a formulation one.
Oleic and linoleic
Skin that is short on linoleic acid and heavy on oleic behaves differently from skin with the opposite balance. Formulators care about this. Labels almost never let a reader see it, and this site does not guess at it from an oil list.