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Undecylenic Acid

What Undecylenic Acid is & what it does

A naturally derived antifungal that helps preserve formulas and control fungal growth. It is plant-based and gentle.

What does Undecylenic Acid do in skincare?

Undecylenic Acid is a fatty acid used in cosmetic formulas mainly as a conditioning and stabilizing ingredient. It is best known in the wider market for antifungal use, and in skincare it can also help with texture and product feel.

Is Undecylenic Acid safe?

Undecylenic Acid has a long record of cosmetic and topical use and is generally well tolerated at the levels used in formulas. As with any fatty acid, undiluted or high concentrations could irritate sensitive skin, so it is used at controlled amounts in finished products.

Is Undecylenic Acid natural or synthetic?

It can be derived from castor oil, making plant-sourced versions available, though it is also produced synthetically. The naming refers to the chemical compound itself, so its origin depends on the specific manufacturing route.

Sunscreens with Undecylenic Acid

We rate 14 sunscreens that contain it, showing the top 10 by overall score:

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