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How we check
Ingredient lists come from Open Beauty Facts (fetched 2026-10-25). We split each list into individual INCI ingredients and run three independent checks. Ingredient lists can be out of date or incomplete, so always check the packaging.
Not medical advice. These checks read the published ingredient list against public rule lists; results vary from person to person, formulas change, and ingredient lists can be incomplete. Ask a dermatologist or your doctor (and in pregnancy, your midwife or obstetrician) before relying on them.
Fungal acne (Malassezia) checker
Modelled on widely shared public fungal-acne (Malassezia folliculitis) ingredient lists (e.g. the Simple Skin Beauty / Sezia-style checkers) and on lab findings that Malassezia uses C11-C24 fatty acids and their esters as food. Lists disagree at the edges; we take a conservative middle line.
| Rule | Rationale |
|---|---|
| Plant oils and butters | Most plant oils and butters are mixtures of C16-C18 fatty acid triglycerides, which Malassezia can break down and feed on. |
| Fatty acids (C12-C24) | Free lauric, myristic, palmitic, stearic and oleic acids are directly usable fatty acids in the range Malassezia needs. |
| Fatty esters | Esters of C12-C24 fatty acids (myristates, palmitates, stearates, oleates, laurates) can be split by Malassezia lipases. |
| Polysorbates | Polysorbates (Tween) are fatty-acid esters; Tween 40/60/80 are classic growth supplements for Malassezia in the lab. |
| Sorbitan esters | Sorbitan stearate/oleate/laurate are fatty esters similar to polysorbates. |
| Glyceryl and PEG fatty esters | Glyceryl stearate, glyceryl oleate and PEG-stearates are emulsifiers built on C16-C18 fatty acids. |
| Ferments | Yeast and bacterial ferment filtrates (Galactomyces, Saccharomyces, Lactobacillus) are often listed as worth avoiding on fungal-acne lists, though evidence is weak. |
| Lanolin and fatty-acid waxes | Lanolin and some ester waxes contain fatty acid esters in the problem range. |
Not flagged: fatty alcohols (cetyl, cetearyl, stearyl alcohol), squalane, mineral oil/petrolatum, caprylic/capric triglyceride (C8-C10), dimethicone. Some lists flag these too.
Verdict: "Likely safe" if no rule matches, otherwise "Contains flagged ingredients" with the list. Evidence for most rules comes from lab growth studies of the yeast, not trials of finished products.
Pore-clogging (comedogenic) checker
Commonly cited public comedogenic rating lists (based on the rabbit-ear assay work of Fulton, 1989, and later compilations). Ratings are for pure ingredients at test concentrations, not finished products.
Each listed INCI item is looked up. Ingredients rated 3+ are flagged. Position matters: an item in the first 5 counts fully, positions 6-15 count 70%, later 40% (later items are usually at lower concentration). Highest weighted score >= 3.5 = High; >= 2 = Moderate; otherwise Low.
| Ingredient | Rating (0-5) |
|---|---|
| algae extract | 5 |
| carrageenan | 5 |
| ethylhexyl stearate | 5 |
| isocetyl stearate | 5 |
| isopropyl isostearate | 5 |
| isopropyl myristate | 5 |
| laureth-4 | 5 |
| myristyl myristate | 5 |
| octyl stearate | 5 |
| oleth-3 | 5 |
| red algae | 5 |
| sodium lauryl sulfate | 5 |
| triticum vulgare germ oil | 5 |
| wheat germ oil | 5 |
| acetylated lanolin alcohol | 4 |
| cetyl acetate | 4 |
| cocoa butter | 4 |
| coconut oil | 4 |
| cocos nucifera oil | 4 |
| ethylhexyl palmitate | 4 |
| isopropyl palmitate | 4 |
| isostearyl isostearate | 4 |
| lauric acid | 4 |
| linseed oil | 4 |
| linum usitatissimum seed oil | 4 |
| octyl palmitate | 4 |
| peg-16 lanolin | 4 |
| stearyl heptanoate | 4 |
| theobroma cacao seed butter | 4 |
| avocado oil | 3 |
| butyl stearate | 3 |
| ceteareth-20 | 3 |
| corn oil | 3 |
| cottonseed oil | 3 |
| decyl oleate | 3 |
| glyceryl stearate se | 3 |
| glycine soja oil | 3 |
| isopropyl lanolate | 3 |
| isostearic acid | 3 |
| mink oil | 3 |
| myristic acid | 3 |
| peg-8 stearate | 3 |
| persea gratissima oil | 3 |
| sorbitan oleate | 3 |
| soybean oil | 3 |
Ratings are indicative only: they were measured on pure ingredients, often in an animal model, and are not proven for finished formulas, where concentration and the rest of the formula matter.
Pregnancy checker
Lists commonly cited in public pregnancy skincare guidance (ACOG patient FAQs, AAD and dermatology reviews of topical agents in pregnancy). Guidance varies and changes; this is a prompt to ask your doctor, not a ruling.
| Rule | Rationale |
|---|---|
| Retinoids | Oral retinoids cause birth defects; topical retinoids (retinol, retinal, retinyl esters, tretinoin, adapalene) are usually advised against in pregnancy as a precaution. |
| Salicylic acid (BHA) | Low-dose salicylic acid in washes is often considered acceptable, but high-strength peels and leave-on use are commonly flagged. Check strength with your doctor. |
| Hydroquinone | Relatively high skin absorption; commonly advised to avoid or minimise in pregnancy. |
| Some chemical sunscreen filters | Oxybenzone, octinoxate and homosalate are absorbed through skin and have been studied for hormone effects; many guides suggest mineral (zinc oxide, titanium dioxide) filters in pregnancy instead. |
| Formaldehyde releasers | These preservatives release small amounts of formaldehyde; often listed to avoid in pregnancy guides. |
| Certain essential oils | Some essential oils (clary sage, rosemary, sage, jasmine, cinnamon, wintergreen, juniper, pennyroyal) are commonly cautioned in pregnancy aromatherapy guidance. |
| Benzoyl peroxide | Often considered acceptable in small amounts, but commonly listed as 'check with your doctor' for regular use. |
Verdict: "No commonly flagged ingredients" or "Contains ingredients to check with your doctor". We never say a product is safe in pregnancy. Ask your doctor, midwife or pharmacist; this is not medical advice.