A monounsaturated omega-9 fatty acid. At low concentrations works as a mild emollient. At meaningful concentrations (typical of olive, avocado, nut oils) it increases stratum corneum permeability and disrupts the barrier – especially in people with atopic dermatitis, rosacea and fungal acne. Comedogenicity rating 2.
Topical application
BLimited evidence. One RCT or several controlled studies with limitations.
Two-sided profile: on dry and normal skin – a gentle emollient in barrier formulas. On sensitive, acne-prone or compromised-barrier skin it raises TEWL and triggers flare-ups (Danby 2013, Vaughn 2018). Also feeds Malassezia – not suitable for fungal acne.
Oleic Acid is a monounsaturated omega-9 fatty acid with 18 carbon atoms (C18:1). Found in high concentration in olive, sunflower, almond, avocado oils. In skin – a component of sebum (15–20%) and intercellular lipids. Mechanism. Emollient and penetration enhancer – integrates into stratum corneum lipids, loosens their structure, facilitates penetration of other actives. At moderate concentrations restores the hydrolipid barrier. At high concentrations disrupts the barrier (increases TEWL), which is used in pharmaceutical formulas to enhance drug absorption. Where applied. Creams and oils for dry and mature skin, Castile soap, lipsticks, balms. Concentration 1–25%, in pure oils up to 80%. Evidence base. Danby 2013 clinical study (n=19) showed that oleic acid disrupts the barrier in newborns and atopic dermatitis patients – reduces hydration and increases TEWL. AAD 2024 recommends avoiding oleic-rich oils (especially olive) in childhood atopy. Linoleic acid, by contrast, restores the barrier. Safety. Comedogenicity 2 of 5 – in acne patients may cause comedones. On dry and mature skin without acne – safe. Pregnancy and lactation – topically safe. Usable neat in massage oils for stretch marks, but avoid on inflamed skin and in atopy.
Irritation potential
MediumAllergen risk
LowPregnancy
SafeSuitable for
The Evigrade extension adds an evidence panel to Wildberries, Goldapple, Letu, iHerb, Sephora and 12 more stores. This ingredient and every other one in the product show evidence-tier, allergen risk and pregnancy/lactation flags at a glance.
Oleic Acid is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
Oleic Acid suits: dry, normal. Use with caution in: oily, combination, sensitive.
Oleic Acid has moderate irritation potential. Sensitive skin may show a transient reaction that usually settles with adaptation.
A monounsaturated omega-9 fatty acid.
On the Fulton scale 2/5 – low comedogenicity. For acne-prone skin, a rating of 3 or higher suggests choosing an alternative.
Published: · updated:
Use with caution
The INCI name is Oleic Acid. It may also appear as: Олеиновая кислота, Omega-9, C18:1.