Is Undecylenic Acid fungal acne safe?
Undecylenic Acid is generally considered safe for fungal-acne-prone skin. C11 unsaturated; actually antifungal - used in antifungal preparations.
Also known as 10-Undecenoic acid
Why this verdict
C11 unsaturated; actually antifungal - used in antifungal preparations.
Fungal acne, properly called malassezia folliculitis, is driven by a yeast that feeds on fatty acids in roughly the C11 to C24 range. An ingredient is a concern when it can supply usable fatty acids in that window, and it is generally fine when it cannot. Chain length and ethoxylation can both change the verdict, which is why the chemical family alone does not decide it. See the full trigger list and how we assess ingredients for the reasoning and sources.
Frequently asked questions
Is Undecylenic Acid safe for fungal acne?
Undecylenic Acid is generally considered safe for fungal-acne-prone skin. C11 unsaturated; actually antifungal - used in antifungal preparations. This is informational only and not a diagnosis; suitability varies by person and formulation.
Why is Undecylenic Acid considered fungal-acne safe?
C11 unsaturated; actually antifungal - used in antifungal preparations. Fungal acne (malassezia folliculitis) is driven by ingredients that supply fatty acids in roughly the C11 to C24 range that the yeast can metabolize; Undecylenic Acid is assessed against that mechanism.
Assessed using: Folliculitis Scout, Simple Skincare Science.
This page is informational only and is not medical advice or a diagnosis. Fungal acne can resemble other skin conditions, and ingredient suitability varies by person and by formulation. Verdicts reflect community-reported data and malassezia lipid research, not a guarantee for your skin. Always patch test and consult a qualified clinician.