Oleic acid is a natural, monounsaturated omega-9 fatty acid that’s found in many plants, including grape seed, olives, and sea buckthorn. It’s the primary fatty acid in olive oil, and believed to play a role in this oil’s cholesterol-lowering benefits when consumed orally.
Interestingly, research has shown that topical application of oleic acid on its own or as olive oil can disrupt skin’s barrier; however, this effect was not observed when oleic acid was blended with other fatty acids and skin-beneficial ingredients. On the upside, this kind of barrier disruption can enhance penetration of other ingredients naturally present in plant oils or in the product, so it’s not necessarily all bad (and, as we mentioned, not bad at all unless you’re applying pure oleic acid or straight olive oil to skin).
In another interesting twist, combining oleic acid with other lipids (fats) boosts its skin-calming ability, thus making oleic acid useful for reducing signs of dryness and sensitivity.
In cosmetics, oleic acid is used as a cleansing agent and texture enhancer. It’s among the more stable fatty acids, and has a unique ability to preserve the effectiveness of more delicate ingredients such as antioxidants by helping to protect them from light and air degradation.
References for this information:International Journal of Nanomedicine, August 2019, pages 6,539-6,553
International Journal of Molecular Sciences, January 2018, ePublication
Biointerphases, March 2017, ePublication
Experimental Dermatology, January 2014, pages 39-44
See fatty acid
About the Experts
Paula Begoun is the best-selling author of 20 books about skincare and makeup. She is known worldwide as The Cosmetics Cop and creator of Paula’s Choice Skincare. Paula’s expertise has led to hundreds of appearances on national and international radio, print, and television including:
The Paula's Choice Research Team is dedicated to busting beauty myths and providing expert advice that solves your skincare frustrations so you can have the best skin of your life!