Is Steareth-100 fungal acne safe?
Steareth-100 is best used with caution for fungal-acne-prone skin. Heavy PEG headgroup may reduce risk; C18 still concerning.
Also known as PEG-100 Stearyl Ether
Why this verdict
Heavy PEG headgroup may reduce risk; C18 still concerning.
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.
Safer swaps
Fungal-acne-safe alternatives in the same category (Fatty alcohol):
Frequently asked questions
Is Steareth-100 safe for fungal acne?
Steareth-100 is best used with caution for fungal-acne-prone skin. Heavy PEG headgroup may reduce risk; C18 still concerning. This is informational only and not a diagnosis; suitability varies by person and formulation.
Why does Steareth-100 trigger fungal acne?
Heavy PEG headgroup may reduce risk; C18 still concerning. Fungal acne (malassezia folliculitis) is driven by ingredients that supply fatty acids in roughly the C11 to C24 range that the yeast can metabolize; Steareth-100 is assessed against that mechanism.
What can I use instead of Steareth-100?
Fungal-acne-safe alternatives in the same category include Butyloctanol, Caprylyl Alcohol, Decyltetradecanol, Hexyldecanol. Fungalscan suggests swaps like these automatically after an avoid or caution result.
Assessed using: Sezia.
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.