Malassezia ingredient finder
Paste an ingredient list. We tell you which names fall in the ingredient classes that published Malassezia growth studies tested — and name the paper for each. What we do not do: say a product is “fungal-acne safe” or unsafe, or diagnose anything. “Fungal acne” is the informal name for Malassezia folliculitis; that is a clinician's call, not an ingredient list's.
What counts as Malassezia-relevant here
Malassezia yeasts cannot make their own fatty acids and grow on lipids from their surroundings. Two papers measured which ones: Wilde & Stewart (1968) and Porro et al. (1976) found growth on free fatty acids of chain length C12 to C24 and none on shorter chains. Standard culture media supply those lipids as polysorbates (Tween) and triglyceride oils (Leeming & Notman 1987; Dixon agar), and polysorbate assimilation is used to tell species apart (Guého et al. 1996). Castor oil and ricinoleic acid are used by some species and not others (Mayser et al. 1997). The yeast secretes lipases that release fatty acids from esters and triglycerides (DeAngelis et al. 2007), which is why esters and plant oils of C12–C24 acids are listed. Everything else on the popular lists — ferments, fatty alcohols, -eth ethoxylates, C8–C10 triglycerides — has no growth study we can cite, so it is shown as not flagged, with the reason.
This is a name check on the list you paste: each ingredient name is tested against the naming rules above. It cannot see trade names, undeclared components, or a brand's own definition of “fungal-acne safe” — that claim is theirs. If a name is missed or wrongly matched, tell us.
Sources
- Wilde PF, Stewart PS. A study of the fatty acid metabolism of the yeast Pityrosporum ovale. Biochem J. 1968;108(2):225–231. — growth on C12–C24 fatty acids, none on shorter chains.
- Porro MN, Passi S, Caprilli F, Nazzaro P, Morpurgo G. Growth requirements and lipid metabolism of Pityrosporum orbiculare. J Invest Dermatol. 1976;66(3):178–182. — confirms the C12–C24 range.
- Leeming JP, Notman FH. Improved methods for isolation and enumeration of Malassezia furfur from human skin. J Clin Microbiol. 1987;25(10):2017–2019. — culture medium using Tween 60, glycerol monostearate and whole-fat milk as the lipid source.
- Guého E, Midgley G, Guillot J. The genus Malassezia with description of four new species. Antonie Van Leeuwenhoek. 1996;69(4):337–355. — Tween 20/40/60/80 assimilation as a species test.
- Mayser P, Haze P, Papavassilis C, Pickel M, Gruender K, Guého E. Differentiation of Malassezia species: selectivity of Cremophor EL, castor oil and ricinoleic acid. Br J Dermatol. 1997;137(2):208–213.
- DeAngelis YM, Saunders CW, Johnstone KR, et al. Isolation and expression of a Malassezia globosa lipase gene, LIP1. J Invest Dermatol. 2007;127(9):2138–2146. — secreted lipase that hydrolyses triglycerides and esters.
Where the popular lists go further than these papers — ferments, fatty alcohols, -eth ethoxylates, the C11 lower bound, fatty-acid soaps — this page says “not flagged” and why. If you know a growth study we have missed, send it and the rule gets a citation.
Looking for pore-cloggers instead?
The main checker matches each ingredient against published comedogenicity ratings with their source and confidence tier. The two checks are independent: a list can match none of the rules on this page and still contain a 5/5 ingredient, or the reverse.