Olive Oil
Plant oil rich in oleic acid (~70%). Feeds Malassezia and disrupts the lipid profile of compromised barriers.
What it does
Olive oil is roughly 70% oleic acid, a C18 monounsaturated fatty acid that supports Malassezia growth and has been shown to disrupt the lipid lamellae of compromised skin barriers in infants and atopic adults. Topical clinical evidence does not support olive oil for barrier repair, and routine use is contraindicated for fungal acne, seborrheic dermatitis, and active eczema-like flares. Cosmetics often use olive-oil derivatives (ethyl olivate, olive squalane) that don't carry the same free-fatty-acid burden — those are tolerated.
The evidence, graded
Graded per the methodology: strong · moderate · emerging · expert consensus. A weak source on a strong claim gets the weaker label.
Also known as
olea europaea fruit oil, olea europaea