How we rate · 🍄 Fungal acne
Fungal-acne-safe sunscreen: which ingredients feed malassezia
If your "breakouts" are small, uniform, itchy bumps that ordinary acne products never fix, you may not have acne at all: you may have fungal acne, an overgrowth of the skin yeast malassezia. It feeds on a very specific set of ingredients, and the surprise is that they barely overlap with the pore-clogging comedogens everyone worries about. A gentle, oil-free, non-comedogenic sunscreen can still be a feast for malassezia. RateMySPF reads the full ingredient list of every sunscreen we catalog and scores how much it feeds the yeast, so below we'll walk through exactly which ingredients drive it, why chain length is everything, and point to the real products that show each pattern.
TL;DR: the ingredients that drive fungal acne
- Oleic acid: a free fatty acid in the C11-24 range malassezia thrives on; one of the most direct feeders
- Linoleic acid: another free fatty acid the yeast assimilates; often hides inside "gentle" plant-oil bases
- Polysorbate 80: a sorbitan-oleate emulsifier; its fatty tail is a classic malassezia substrate, so we weight it heavily
- Glyceryl stearate: a C18 emulsifier ester; the workhorse of cream bases and a steady feeder when it sits high
- Isopropyl myristate: a C14 slip ester that feeds the yeast and clogs pores, flagged on both our breakout axes
- Ceteareth-20: an ethoxylated fatty-alcohol emulsifier; the fatty chain still feeds, so we count the family
- Lecithin: a fatty phospholipid emulsifier from soy; rich in the fatty acids malassezia uses
- Lanolin: wool fat, a dense mix of fatty esters and acids, a feeder beloved in balmy formulas
Why fungal acne needs its own score
Fungal acne is a nickname for malassezia folliculitis: not bacterial acne at all, but an overgrowth of a yeast that lives on everyone's skin. It shows up as clusters of small, same-size, often itchy bumps, usually on the forehead, hairline, chest and back, and it famously refuses to clear with the benzoyl peroxide and salicylic acid you'd throw at ordinary spots. The reason it's a separate problem is a quirk of the yeast's biology: malassezia can't make its own fatty acids. It lacks the genes for fatty-acid synthase, so it has to scavenge them from its surroundings, which means the lipids in your skincare are quite literally its food supply.
Crucially, it's picky about which lipids. Malassezia assimilates medium-to-long chain fatty acids, roughly C11 to C24, and the esters and oils built from them. Shorter chains, the C8-C10 ones like caprylic and capric acid, it can't use, and they can even be mildly inhibitory. That single fact does most of the work in this score: we classify each ingredient by the fatty acid it's built from, not by its family name. So caprylic/capric triglyceride (MCT), dicaprylyl carbonate and triheptanoin are safe, while glyceryl stearate, isopropyl myristate and polysorbate 80 feed the yeast, even though all of them are "esters."
This is why fungal acne earns its own axis instead of folding into our comedogenic score. The two lists barely overlap. Plenty of non-comedogenic sunscreens, the gentle, oil-free fluids dermatologists recommend for acne, are loaded with malassezia feeders like linoleic acid and polysorbates; meanwhile a few classic pore-cloggers (coconut oil) happen to feed the yeast too. Merging them would falsely reassure a fungal-acne sufferer or over-scare everyone else. One more thing to set expectations: feeders are everywhere in emulsified sunscreen, so this score behaves as an earned green flag, a truly clean formula is the exception, and we keep this axis out of the overall score: it's a flag for people who know they're fungal-acne-prone, not a mark against a product for everyone else.
▲ Free fatty acids and polysorbates: the top-tier feeders
Raises risk
The most direct feeders are free fatty acids in the C11-24 range, above all oleic and linoleic acid, and the polysorbate / sorbitan-ester emulsifier family (polysorbate 60, polysorbate 80, sorbitan oleate and friends). The fatty acids are food in their rawest form; the polysorbates carry a fatty tail (oleate, stearate, laurate) that the yeast cleaves and eats. We penalise both hardest of all the levers, and as always position drives everything: one of these at the very top of the list is a meaningful share of the formula.
Here's the headline that catches people out: this is where the gentle, derm-loved sunscreens stumble. CeraVe's Hydrating Sunscreen is non-comedogenic and beloved by acne-prone skin, yet it's built on linoleic acid plus polysorbates, so on this axis it scores near zero. That isn't a knock on CeraVe for most people, it's a perfect illustration of why fungal acne is a different question from clogged pores. A polysorbate sitting alone in an otherwise clean Biore gel, by contrast, lands only at "medium."
Free-fatty-acid and polysorbate feeders, note how high they sit in each list:
- 5 long-chain (C12+) esters that feed Malassezia (Glyceryl Stearate, PEG-100 Stearate, PEG-8 Laurate)
- 3 polysorbate/sorbitan emulsifiers that feed Malassezia (Polysorbate 60, Sorbitan Stearate, Sorbitan Isostearate)
- 1 free fatty acids that feed Malassezia (Myristic Acid)
- 5 long-chain (C12+) esters that feed Malassezia (PEG-40 Stearate, Polyglyceryl-6 Polyricinoleate, Steareth-2)
- 2 free fatty acids that feed Malassezia (Linoleic Acid, Linolenic Acid)
- 2 oils/butters that feed Malassezia (Lecithin, Hydrogenated Lecithin)
- 3 polysorbate/sorbitan emulsifiers that feed Malassezia (Polysorbate 60, Polysorbate 80, Sorbitan Sesquioleate)
▲ Plant oils, butters and lanolin
Raises risk
Almost every plant oil and butter is a triglyceride of exactly the long-chain fatty acids malassezia wants, so as a group they feed it: sunflower, olive, jojoba aside, argan, shea and cocoa butter, plus animal-derived lanolin and soy lecithin, and castor oil. These are the richness ingredients, and they cluster in two formats in our catalog: "natural" mineral sunscreens that lean on plant oils for slip, and balmy sticks that are built almost entirely out of oils and waxes.
The stick format is the clearest tell. La Roche-Posay and Vichy both make excellent stick sunscreens, but a stick is an anhydrous block of oils and esters, so the same brand whose watery fluid scores clean can have a stick that lands deep in the high tier. (Two oils we deliberately treat as safe: squalane and the mineral hydrocarbons. Squalane is fully saturated and not a usable substrate, though note its cousin squalene, with the extra double bonds, is a genuine feeder.)
Oil- and butter-forward formats, sticks especially, with the feeders up top:
- 4 oils/butters that feed Malassezia (Glycine Soja Oil, Butyrospermum Parkii Fruit, Theobroma Cacao Seed Butter)
- 1 long-chain (C12+) esters that feed Malassezia (Isopropyl Palmitate)
- 2 different Malassezia-feeding families high in the list
- 4 oils/butters that feed Malassezia (Glycine Soja Oil, Butyrospermum Parkii Fruit, Theobroma Cacao Seed Butter)
- 1 long-chain (C12+) esters that feed Malassezia (Isopropyl Palmitate)
- 2 different Malassezia-feeding families high in the list
- 2 oils/butters that feed Malassezia (Helianthus Annuus Seed Oil, Lecithin)
▲ Fatty esters and ethoxylated emulsifiers: it's the chain length
Raises risk
This is the subtle tier, and where most fungal-acne ingredient lists online get it wrong. Emulsifier and emollient esters are only feeders when their fatty part is C12 or longer. So glyceryl stearate, isopropyl myristate, polyglyceryl-3 oleate, the PEG-stearates and the ethoxylated fatty alcohols (ceteareth-20, steareth-21, laureth-7) all carry a long chain and feed; meanwhile glyceryl caprylate, dicaprylyl carbonate and C12-15 alkyl benzoate, which look just as "ester-y," are C8-C10 or aromatic and don't. Our score reads the chain, not the word "glyceryl," so it can tell those apart.
Because these esters are the backbone of nearly every modern lotion and watery gel, a single one mid-list is a light "low," not a red flag. EltaMD UV Clear, the acne-prone darling that scores a perfect zero on our comedogenic axis, picks up just one ester here and still sits at a comfortable "low." The much-loved Biore UV Aqua Rich watery essence lands at "medium" on the same logic. These aren't products to avoid, they're products to be aware of if the yeast is your specific problem.
Ester-driven formulas, the chain length is what we're reading:
- 1 long-chain (C12+) esters that feed Malassezia (Oleth-3 Phosphate)
- 4 long-chain (C12+) esters that feed Malassezia (Isopropyl Palmitate, Glyceryl Stearate, Glyceryl Behenate)
- 1 ubiquitous fatty ingredients (Palmitic Acid), weak Malassezia signal
- 3 long-chain (C12+) esters that feed Malassezia (Myristyl Myristate, Glyceryl Stearate, PEG-100 Stearate)
- 1 ubiquitous fatty ingredients (Stearic Acid), weak Malassezia signal
▲ When feeders stack near the top
Raises risk
Feeders rarely travel alone. A rich cream might open with glyceryl stearate, then a plant oil, then polysorbate 60, three separate feeder families in the first few ingredients. That isn't one questionable emollient, it's a base built out of food. So when two or more distinct feeder families land high in the list (position seven or above), we add a dedicated stacking penalty on top of the individual hits.
This is the signature of almost everything in our high tier: the worst scores aren't earned by a single ester but by a whole oily, emulsified base. Day creams and "nourishing" moisturisers with SPF are the usual offenders, they're formulated for comfort and richness, which on this axis reads as a stacked feeder load.
Stacked-feeder formulas, where the base itself is the problem:
- 1 free fatty acids that feed Malassezia (Myristic Acid)
- 2 long-chain (C12+) esters that feed Malassezia (Glyceryl Stearate, PEG-100 Stearate)
- 2 ubiquitous fatty ingredients (Stearic Acid, Palmitic Acid), weak Malassezia signal
- 2 long-chain (C12+) esters that feed Malassezia (Glyceryl Stearate, PEG-100 Stearate)
- 2 oils/butters that feed Malassezia (Prunus Armeniaca Oil, Hydrogenated Lecithin)
- 2 polysorbate/sorbitan emulsifiers that feed Malassezia (Polysorbate 20, Sorbitan Stearate)
- 2 oils/butters that feed Malassezia (Prunus Amygdalus Dulcis Oil, Butyrospermum Parkii Fruit)
- 1 long-chain (C12+) esters that feed Malassezia (Glyceryl Stearate)
- 2 different Malassezia-feeding families high in the list
● The watchlist: flagged, but not penalised
Neutral
A few ingredients look like they should count and don't, so we surface them at zero points for transparency rather than penalise them. The big one is undecylenic acid: it's a C11 fatty acid, which by chain length should feed, except it's actually a recognised OTC antifungal (the active in old athlete's-foot remedies). It treats malassezia, it doesn't feed it, so penalising it would be exactly backwards. Ferments like galactomyces and saccharomyces filtrate get a watchlist note too: community lists fear them, but there's no lipid-dependence mechanism, so they cost nothing.
Jojoba (simmondsia chinensis) is the third: chemically it's a wax ester rather than a triglyceride, poorly used by the yeast, so we exclude it from the oil penalty and just note it. A formula whose only flag is jojoba can still score a clean "safe." The point of this tier is to show our work: we noticed these ingredients and decided, with a reason, that they don't belong in the number.
Watchlist notes shown but not counted, these stay clean or near-clean:
- 2 long-chain (C12+) esters that feed Malassezia (Polyglyceryl-3 Methylglucose Distearate, Sodium Stearoyl Glutamate)
- 2 oils/butters that feed Malassezia (Helianthus Annuus Seed Oil, Lecithin)
▼ Why a clean "safe" is earned, not given
Lowers risk
Because feeders are so common, a genuinely safe score means something. It takes a formula built on the ingredients malassezia can't eat: silicones (dimethicone, cyclopentasiloxane), mineral hydrocarbons (squalane, mineral oil, petrolatum), MCT and C8-C10 esters, humectants (glycerin, hyaluronic acid), and water, with no fatty acids, plant oils or long-chain emulsifiers near the top. That describes the modern silicone-in-water gels and many fluid fragrance-free formulas, which is why they dominate the safe tier.
The standouts are the lightweight aqueous gels: Vichy Mineral 89 with SPF, Bioderma Photoderm and the Cetaphil Sun gels score a perfect 100, no feeders at all. If fungal acne is your problem, these textures, watery gels and silicone fluids rather than rich creams, sticks or "natural" oil-based lotions, are the safest place to start, and our filter takes you straight to them.
Silicone, mineral and aqueous bases that score a clean, fungal-safe zero risk:
How to pick a fungal-acne-safe sunscreen
Start from texture. The single best predictor of a low feeder load is format: a watery gel or a silicone-based fluid is far more likely to be clean than a rich cream, a balmy stick or a "natural" oil-rich lotion. Filter our catalog to a safe fungal-acne score and you'll be looking at exactly those: the fragrance-free aqueous gels and dimethicone fluids that carry no fatty acids, plant oils or long-chain emulsifiers. "Oil-free" on the label is a weak hint here and "non-comedogenic" is almost useless, since it's measuring a different thing, so let the ingredient list (which is what our score reads) decide.
Keep two caveats in mind. First, this is a propensity flag, not a diagnosis: most people aren't fungal-acne-prone, and if a sunscreen has never given you those itchy uniform bumps, a scary score here isn't a reason to drop something that works. It only matters if malassezia is genuinely your issue, ideally confirmed by a dermatologist. Second, a sunscreen is one product in a routine; a perfectly clean SPF won't help if the moisturiser under it is an oil-rich feeder. Treat this score as one input, match it to your own track record, and when in doubt, patch test.
We rate every sunscreen in our catalog for fungal acne.
Browse fungal-acne safe sunscreensFrequently asked questions
What is fungal acne?
Fungal acne is the common name for malassezia folliculitis, an overgrowth of a yeast that naturally lives on skin. It looks like clusters of small, uniform, often itchy bumps, typically on the forehead, hairline, chest and back, and it doesn't respond to regular acne treatments. It isn't bacterial acne, so the ingredients that trigger it are different, which is why we score it on its own axis.
How is fungal acne different from regular (comedogenic) acne?
Comedogenic acne is pores physically clogged by heavy oils and esters. Fungal acne is a yeast overgrowth fed by specific fatty acids, esters and plant oils. The ingredient lists barely overlap: a non-comedogenic sunscreen can be full of malassezia feeders, and vice versa. That's exactly why we keep two separate scores rather than one "breakout" number.
Which sunscreen ingredients feed fungal acne?
The main feeders are free fatty acids like oleic and linoleic acid; polysorbates and sorbitan esters; most plant oils and butters, plus lanolin, lecithin and castor oil; and fatty esters and ethoxylated emulsifiers with a C12-or-longer chain (glyceryl stearate, isopropyl myristate, ceteareth-20). The common thread is a C11-24 fatty acid the yeast can eat.
Why does chain length (C11-24) matter so much?
Malassezia can't make its own fatty acids, so it scavenges them, and it can only use medium-to-long chains, roughly C11 to C24. Shorter C8-C10 lipids (caprylic and capric acid, MCT) it can't use and can even be mildly inhibited by. So we classify each ingredient by the fatty acid it's built from: glyceryl stearate (C18) feeds, glyceryl caprylate (C8) doesn't, even though both are "glyceryl esters."
Are squalane and mineral oil safe for fungal acne?
Yes. Squalane is a fully saturated hydrocarbon, not a fatty acid the yeast can use, and mineral oil, petrolatum and other hydrocarbons offer no substrate at all. They're among the safest emollients for fungal-acne-prone skin. One caution: squalene, the unsaturated version sometimes listed instead of squalane, is a genuine feeder, so the spelling matters.
Is caprylic/capric triglyceride (MCT) fungal-acne safe?
Yes. MCT is built from C8-C10 fatty acids, below the range malassezia can use, so we treat it as safe and it's one of the ingredients that lets a formula earn a clean score. Commercial grades can carry a tiny fraction of longer-chain impurity, but not enough to flag.
Why is undecylenic acid not penalised when it's a C11 fatty acid?
By chain length it would feed, but undecylenic acid is actually a recognised OTC antifungal, the active ingredient in classic athlete's-foot treatments. It suppresses malassezia rather than feeding it, so penalising it would be backwards. We show it as a zero-point watchlist note for transparency.
Do ferments like galactomyces feed fungal acne?
Some community lists fear them, but there's no lipid-dependence mechanism that would make galactomyces or saccharomyces ferment filtrate feed malassezia. We note them at zero points so you can see we considered them, but they don't cost a product anything.
Is jojoba oil safe for fungal acne?
Mostly. Jojoba is chemically a wax ester rather than a triglyceride of free fatty acids, so the yeast uses it poorly. We exclude it from the oil penalty and just note it, which means a formula whose only flag is jojoba can still score "safe."
Why do so many gentle, non-comedogenic sunscreens score badly here?
Because "gentle" and "non-comedogenic" describe pore-clogging, a different problem. Many derm-recommended fluids are built on linoleic acid, polysorbates and fatty emulsifiers that don't clog pores but do feed malassezia. CeraVe's Hydrating Sunscreen is the textbook case: lovely for most acne-prone skin, but a strong feeder if fungal acne is your specific issue.
Why isn't fungal acne part of the overall score?
Because feeders are nearly universal in emulsified sunscreen and most people aren't fungal-acne-prone, so weighting every product down for it would be misleading. We keep it as a standalone flag, like a slider, that surfaces for people who know malassezia is their problem, without dragging down the headline number for everyone else.
What sunscreen texture is safest for fungal acne?
Lightweight watery gels and silicone-based fluids are safest: they're built on water, silicones, humectants and short-chain or hydrocarbon emollients with few or no feeders. Rich creams, balmy sticks and "natural" oil-based lotions are the riskiest, since they lean on the plant oils and fatty emulsifiers the yeast eats. Filter our catalog to a safe score and you'll land on the gels first.
Does a high fungal-acne score mean a sunscreen will break me out?
No. It's a propensity flag for fungal-acne-prone skin, not a prediction. Most people tolerate these ingredients with no trouble at all, and many fungal-acne sufferers are fine with mild feeders low in the list. If a product has never caused those itchy, uniform bumps for you, the score isn't a reason to stop using it. Treat it as one input alongside your own experience.