Ingredient · dataset v56
Stearic Acid and fungal acne
May trigger · Strong evidence
Why it's a potential trigger
An 18-carbon staple fat that Malassezia yeast readily takes up; a core part of what it harvests from skin oils.
Ubiquitous in both skin and cosmetics.
Evidence strength
Strong evidence (3/3)
Function
Fatty acid
Fatty acids (~C11–C24): the yeast takes these up directly as food — the core trigger class.
Also listed as
Octadecanoic Acid
Checked products with this ingredient (1)
Product types: Antifungal treatments
Antifungal treatments (1)
Products without this ingredient
- COSRX The Niacinamide 15 Serum 20 ml
- K18 Peptide Prep Detox Shampoo 8.5 oz
- Jane Iredale Powder-Me SPF 30 Dry Sunscreen Nude
- Pyunkang Yul Essence Toner 200 ml
- Biossance 100% Squalane Oil 3.3 oz
- Mixsoon Glacier Water Ice Soothing Gel 150 ml
Related fatty acid
- Azelamide MEA — No known trigger
- Capric Acid — No known trigger
- Caprylic Acid — No known trigger
- Isostearic Acid — May trigger · Moderate evidence
- Lauric Acid — May trigger · Moderate evidence
- Linoleic Acid — May trigger · Moderate evidence
- Myristic Acid — May trigger · Limited evidence
- Oleic Acid — May trigger · Strong evidence
Sources
- Gaitanis et al. 2012 — Malassezia genus review: lipid dependence, C11-24 fatty-acid utilization (Clin Microbiol Rev)
- EU CosIng database — search the INCI name
Last reviewed: 2026-10-13 (dataset v56).
Questions
Does Stearic Acid trigger fungal acne?
We flag it as a potential trigger (strong evidence). That means it belongs to a class the Malassezia yeast is known to feed on — not that every product with it will cause a flare. Concentration, formulation and individual skin chemistry matter.
Does Stearic Acid feed Malassezia?
Yes: we flag Stearic Acid as a potential trigger (strong evidence). It belongs to a class Malassezia is known to feed on — not a claim that every product with it causes a flare. Concentration, formulation and individual skin chemistry matter.
How confident is this call?
Strong evidence: An 18-carbon staple fat that this yeast readily takes up; a core part of what it harvests from skin oils.
Is this medical advice?
No. We screen ingredient lists; we never diagnose, treat, or certify products. When in doubt, ask a dermatologist.
Check a full list containing Stearic Acid →
Not medical advice: we screen ingredient lists for potential triggers — we never diagnose, treat, or certify products. Dataset v56.