Ingredient

Oleic Acid

A monounsaturated omega-9 fatty acid (C18:1) that is the dominant fatty acid in olive, avocado, and many other oils.

Key facts

INCI name: Oleic Acid
Evidence grade: limited evidence
In our catalog: Found in 51 of the 2,588 products we've decoded
Fungal acne: Reported trigger
Reviewed: July 2, 2026

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Similar ingredients

others that do something alike

Squalane

A lightweight, skin-identical oil that moisturizes without clogging.

Argan oil

Argan oil; smooths frizz and adds shine.

Bakuchiol

A plant-based alternative to retinol with similar smoothing benefits and less irritation.

Good to know

Fungal-acne triggercaution

Can feed Malassezia yeast — a trigger for fungal acne (pityrosporum folliculitis) in people prone to it.

What it does

limited evidence

In cosmetics it works as a rich emollient and, in small amounts, an emulsifier; because it has only one double bond it produces heavier, more occlusive oils than linoleic acid.

Benefits

Rich, nourishing emollient that softens and conditions dry or mature skin
Acts as an emulsifier/emulsion stabilizer in small amounts in formulas

Side effects

Considered comedogenic, so oleic-rich oils can clog pores and worsen breakouts on acne-prone skin
Well documented as a penetration enhancer that can disrupt the stratum corneum barrier, which may increase irritation or sensitivity for some, especially on already-compromised skin
Sits within the C11-C24 fatty-acid range that lipid-dependent Malassezia yeast can feed on, so it is generally flagged as a potential fungal-acne (Malassezia folliculitis) trigger