Linoleic Acid

Linoleic acid is an essential omega-6 fatty acid the body cannot synthesise — and acne-prone skin has been shown to have abnormally low linoleate levels in its sebum. Topical application at 1–2% helps normalise sebum composition, reduces follicular hyperkeratosis, and has documented comedolytic effects. As a precursor of ceramide 1 linoleates it also strengthens the barrier, and via its conversion to anti-inflammatory eicosanoid metabolites it calms redness. Dry, acne-prone, and barrier-compromised skin benefit most; it is abundant in rosehip, sunflower, and safflower oils. Evening use in oil form is common; oxidised products should be discarded.