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Li

Linoleic Acid

Linoleic AcidBarrier

Essential fatty acid in the barrier matrix. Acne-prone skin tends to be deficient in linoleic acid relative to oleic.

What it does

Linoleic acid is one of the two essential fatty acids the body cannot synthesize. In the skin, it's part of the barrier lipid matrix (with ceramides and cholesterol) and a precursor to ceramide-1, the most abundant ceramide subtype. Studies in acne-prone skin show a relative deficiency in linoleic vs oleic acid; topical linoleic-rich oils (safflower, hemp seed, evening primrose) can support barrier function in those users.

The evidence, graded

expert consensusFungal acne (Malassezia folliculitis) is fed by fatty acids and esters with C11-C24 chain lengths. Oils in that range are frequently reported to worsen it, including oils marketed as pore-friendly or 'safe for acne-prone skin'. Squalane, MCT, and mineral oil fall outside the range and are typically tolerated.Rubenstein 2014 · Journal of Clinical and Aesthetic Dermatology
emergingThe skin's barrier is built from ceramides, cholesterol, and free fatty acids in a roughly 1:1:1 to 3:1:1 ratio. Moisturizers formulated to mimic that ratio support barrier repair more than any one lipid alone.Man 1996 · Journal of Investigative Dermatology

Graded per the methodology: strong · moderate · emerging · expert consensus. A weak source on a strong claim gets the weaker label.

Also known as

omega-6 fatty acid

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