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Fungal acne checker

Paste an ingredient list — or pick a product — and see which ingredients can feed Malassezia, the yeast behind fungal acne.

Nothing you paste is stored. A check is an aid, not a diagnosis.

How the check works

Malassezia is a yeast that lives on nearly everyone’s skin. It cannot build its own fatty acids, so it feeds on the ones it finds — chains of 11 to 24 carbons — and its enzymes free them from fats in sebum and in skincare.

Trigger esters of those fatty acids (isopropyl myristate, glyceryl stearate), polysorbates, plant oils and butters, triglycerides, free fatty acids and their salts, lanolin, lecithin, beeswax.
Possible ferments, fatty alcohols (cetyl, cetearyl), squalene — weaker evidence, worth avoiding during a flare.
Not flagged caprylic/capric triglyceride (MCT oil), squalane, mineral oil, petrolatum, silicones, glycerin, essential oils, and emulsifiers like ceteareth-20.

The evidence comes mostly from yeast grown in the lab on single fatty acids; a finished formula and real skin are more complicated, so the checker leans cautious. It is an aid for choosing products, not a diagnosis.

Fungal-acne safe picks

Questions

What is fungal acne?

Fungal acne (Malassezia folliculitis) is not acne at all: it is a yeast infection of the hair follicles. Malassezia lives on almost everyone’s skin and causes trouble only when it overgrows — usually as small, uniform, itchy bumps on the forehead, chest or back that do not respond to ordinary acne treatments.

Which ingredients can make fungal acne worse?

Malassezia cannot make its own fatty acids, so it feeds on the ones on your skin: fatty acids with 11 to 24 carbons, and the esters, oils, butters and polysorbates its enzymes break them out of. That is what this checker flags — isopropyl myristate, glyceryl stearate, polysorbate 80, most plant oils and butters, stearic and lauric acid, lanolin, lecithin.

Are squalane and MCT oil safe for fungal acne?

Yes. Squalane is a hydrocarbon, not a fat, and caprylic/capric triglyceride (MCT oil) is built from 8- and 10-carbon chains — too short for Malassezia to use. Mineral oil, petrolatum and silicones are safe for the same reason.

Is cetearyl alcohol safe for fungal acne?

Fatty alcohols such as cetyl, stearyl and cetearyl alcohol are not fatty acids, and most people with fungal acne tolerate them. Some cautious lists still avoid them, so we show them as “possible”, not as triggers.

How do I tell fungal acne from regular acne?

Fungal acne bumps are small and all the same size, often itch, and cluster where you sweat. Regular acne mixes blackheads, whiteheads and deeper spots. If bumps do not budge with benzoyl peroxide or antibiotics, ask a dermatologist — a quick skin scraping confirms it.

Does “fungal-acne safe” mean a product will clear my skin?

No. It means none of its ingredients is a known Malassezia food. Treatment is antifungal — ketoconazole or zinc pyrithione washes, sometimes oral antifungals — prescribed or recommended by a dermatologist.

Sources

  1. Gaitanis G, Magiatis P, Hantschke M, Bassukas ID, Velegraki A. The Malassezia genus in skin and systemic diseases. Clin Microbiol Rev. 2012;25(1):106–141.
  2. Xu J, Saunders CW, Hu P, et al. Dandruff-associated Malassezia genomes reveal convergent and divergent virulence traits shared with plant and human fungal pathogens. PNAS. 2007;104(47):18730–18735.
  3. Henning MAS, Hay R, Rodriguez-Cerdeira C, et al. Position statement: recommendations on the diagnosis and treatment of Malassezia folliculitis. J Eur Acad Dermatol Venereol. 2023;37(7):1268–1275.

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