Linoleic Acid is best treated as a cautious avoid during an active seb derm flare or when you are following a strict Malassezia-conscious routine. It is a C18 polyunsaturated fatty acid used to condition skin, and laboratory evidence shows that new laboratory work found hyphal changes in a tested Malassezia furfur strain under specific culture conditions. That is a meaningful theoretical concern, but it does not prove that every product containing Linoleic Acid will worsen seborrheic dermatitis.

A separate human skin study found irritation and water-loss changes after concentrated, occluded exposure, but it did not test normal cosmetics or seb derm. A small amount in a rinse-off product is also a different exposure from a fatty-acid-rich leave-on cream. If you want the simplest option during a flare, choose a formula without Linoleic Acid; otherwise stop if a product repeatedly increases itching, redness, tightness or stinging.