Fungal acne safe checker (Malassezia triggers)

This fungal acne safe checker reads a skincare ingredient list and flags every entry that fits one stated rule: Malassezia yeasts metabolise fatty acids of roughly C11 to C24, so esters of those acids, ethoxylated fatty alcohols, free fatty acids and most plant oils are flagged. The rule is printed below in full.

Nothing is uploaded. Matching runs inside your browser, no account is involved, and the result is never stored. Malassezia folliculitis is a clinical diagnosis, and this page screens text.

The rule this checker applies

The rule has one premise and seven patterns. Malassezia yeasts are lipid-dependent: they take fatty acids from their surroundings rather than synthesising their own, and the usable range is roughly C11 to C24. Every pattern below describes a way that range shows up in an INCI name, which is why the checker matches by shape rather than by membership.

The plant-oil pattern deserves a note, because it is the one people are surprised by. It matches the suffix of the parsed name rather than a list of plants. A list of plants promised completeness it could never deliver: there are thousands of botanical species in cosmetics, and the label rarely gives the common name. The label entry Cocos Nucifera (Coconut) Oil normalises to cocos nucifera oil, in which the word coconut no longer appears at all, so a plant list would miss it while a suffix rule catches it.

Getting to that normalised form is its own small piece of engineering, and it decides how many lines survive to be judged. The parser splits on brackets by one test: a comma inside the brackets means a nested list, as on a food label, and no comma means the brackets gloss the name beside them, as on an INCI label. Without that test a single ingredient shatters into three entries that do not exist, and the tally of recognised lines — the number the whole result rests on — stops meaning anything.

The exceptions, and why each one is an exception

Six exception groups, eighteen names in total, are checked before any pattern runs. Without them the rule lies in the opposite direction: squalane and MCT oil look like esters by the morphology of their names, the yeast cannot use either, and a checker that flagged them would send people away from the two lipids most often reached for.

The caprylic entry shows how the two halves interlock. The ester pattern deliberately includes caprylate and caprate so that stray C8–C10 esters are not silently ignored, and the exception list then pulls caprylic/capric triglyceride back out by name. Rule first, exception second, both published — that ordering is the whole design.

Why a stated rule beats a copied list

Every other Malassezia checker matches against a trigger list, and those lists trace back to a handful of community compilations that carry no open licence and no stated method. Copying one would mean inheriting somebody else’s judgement calls without being able to explain a single entry. This page states the criterion instead, so a result can be re-derived by hand.

A copied list can only tell you that somebody once decided an ingredient was a trigger. A published rule tells you why, which means you can apply it yourself to the one name the checker has never seen.

It also fixes the coverage problem honestly. A list is finite and the ingredient dictionary is not: new esters and new botanical extracts appear on labels constantly. A rule expressed as name morphology reaches ingredients that were never entered into any database, and where it fails it fails visibly, in the not-recognised column rather than in silence.

How to read the three answers

The output separates three states, and the middle one is the state most checkers hide. A binary tool that prints “no triggers found” over four unparsed lines has converted a gap in its own vocabulary into a statement about your product. The tally at the top of every result says how many of the lines were actually read.

The order of the output is deliberate as well. Matches come first, unrecognised names come second, and cleanly matched-nothing lines come last, because the unrecognised group is the part that changes how much weight the rest deserves. Four unreadable lines out of thirty-two make a clean result a much weaker statement, and burying that at the bottom would be a design choice about comfort rather than accuracy.

Fungal acne and comedonal acne are different questions

Malassezia folliculitis and comedonal acne are separate conditions with separate ingredient questions, and they are told apart by a clinician examining the skin, never by an ingredient list. An ingredient can be flagged by one screen and cleared by the other, which is exactly why this site keeps two tools on two URLs instead of one combined verdict.

If the concern is blackheads and closed comedones rather than the uniform itchy papules of folliculitis, the pore-clogging ingredients checker matches against a published list with ratings attached, and how comedogenic ratings are produced explains why two reputable lists can contradict each other on the same material.

Some ingredients appear in both screens for unrelated reasons, and coconut oil on both screens is the clearest case: it carries a rating of 4 on the published comedogenic list, and separately it is a plant oil rich in lauric acid, so the Malassezia rule flags it too. Two different criteria, one ingredient, no shared logic.

Where this checker is the wrong tool

A rule that reads name shape cannot read a formulation. It does not know concentration, it does not know whether an ester sits at trace level or carries the texture, and it flags a whole category where a human curator might have cleared one member of it. Those are real limits, and they are the reason this page publishes the rule rather than a score.

What this page will not tell you

No regulator issues Malassezia trigger lists, and none issues comedogenic lists either. There is no FDA, EU or global body that certifies, audits or standardises either kind of list, published versions disagree with each other, and this page is a private compilation like all the others — the only difference is that its criterion is written down where you can argue with it.

It will also not tell you whether a named product from a named brand will break you out. That is a claim about a specific company’s goods and this site does not make those. The checker reads only text you paste in yourself, the result is generated in your browser, and it is never stored or published.

None of this is medical advice, and nothing here diagnoses anything. Persistent, itchy or painful breakouts are worth taking to a dermatologist, who can distinguish Malassezia folliculitis from comedonal acne and from rosacea — three conditions that an ingredient list cannot tell apart.