Every claim, its source.

Safety-checker rules, cited

Each verdict in the pregnancy and fungal-acne checkers — and the matching chips on ingredient pages — links straight here, to the rule it fired and the sources behind it. Evidence is graded honestly: "limited" means the basis is mechanistic, in-vitro, or an absence of a safety signal, not proof.

Pregnancy checker

• Retinoids (retinol, retinaldehyde, tretinoin, adapalene, retinyl esters)AvoidStrong evidence

  Strong dermatology consensus is to avoid topical retinoids in pregnancy. Oral retinoids are proven teratogens; topical absorption is low (~1–2% for tretinoin) and prospective human studies have not shown a clear rise in malformations, but because the same vitamin-A signalling pathway is involved, the risk-benefit ratio is judged unfavourable and guidelines contraindicate them. This is precaution, not evidence of harm from creams.

  • Skin Changes and Safety Profile of Topical Products During Pregnancy (peer-reviewed review). PMC ↗
  • Topical retinoid use in women of reproductive age and risk of major congenital malformations: a Nordic cohort study. Br J Dermatol 2026 ↗
• HydroquinoneAvoidModerate evidence

  Best avoided in pregnancy — not because harm is proven (a small human series showed no increase in adverse events) but because systemic absorption is unusually high for a topical: roughly 35–45% of an applied dose is absorbed, far more than most actives. With safe brightening alternatives available (azelaic acid, vitamin C, niacinamide + sunscreen), the cautious course is to skip it.

  • Skin Changes and Safety Profile of Topical Products During Pregnancy (peer-reviewed review). PMC ↗
  • Hydroquinone. StatPearls / NCBI Bookshelf ↗
• Salicylic acid (BHA)CautionLimited evidence

  Depends on dose and area. Low-concentration, rinse-off or leave-on OTC salicylic acid (the ~0.5–2% in most cleansers/toners) is endorsed by ACOG for use in pregnancy — absorption is minimal over small areas. The caution is for HIGH-strength salicylic peels and whole-body or occluded use, where salicylate exposure is higher; those are best deferred. Evidence for real-world topical risk is limited, so this is a concentration nuance, not a blanket ban.

  • Topical Acne Treatments. MotherToBaby Fact Sheets (NCBI Bookshelf) ↗
  • Skin Changes and Safety Profile of Topical Products During Pregnancy (peer-reviewed review). PMC ↗
• Benzoyl peroxideGenerally fineModerate evidence

  Generally considered fine in pregnancy and a first-line acne option per ACOG. About 5% is absorbed through skin and is then fully metabolised to benzoic acid and excreted, so systemic exposure is very low; no signal for congenital malformation. Start low (2.5%).

  • Topical Acne Treatments. MotherToBaby Fact Sheets (NCBI Bookshelf) ↗
  • Skin Changes and Safety Profile of Topical Products During Pregnancy (peer-reviewed review). PMC ↗
• Azelaic acidGenerally fineModerate evidence

  One of the preferred actives in pregnancy — it tackles acne, redness and pigment. It occurs naturally in grains, absorption is low (~3–8%), and animal studies showed no harm at high doses. A practical, evidence-supported choice.

  • Skin Changes and Safety Profile of Topical Products During Pregnancy (peer-reviewed review). PMC ↗
  • Topical Acne Treatments. MotherToBaby Fact Sheets (NCBI Bookshelf) ↗
• Glycolic / lactic acid (AHA)Generally fineModerate evidence

  Low-strength AHAs are considered safe topically — reviews put the reassuring range at up to ~10% with pH above 3.5, where systemic absorption is minimal. As with salicylic acid, the only real caution is high-percentage in-office peels. Keep daily SPF, since AHAs raise UV sensitivity.

  • Skin Changes and Safety Profile of Topical Products During Pregnancy (peer-reviewed review). PMC ↗
  • Chua-Gocheco A, Bozzo P, Einarson A. Safety of skin care products during pregnancy. Can Fam Physician 2011. PMC ↗
• Niacinamide (vitamin B3)Generally fineLimited evidence

  Widely regarded as one of the safest pregnancy actives — it is a form of vitamin B3, supports the barrier, calms redness and helps pigment, with no known safety concern in topical use. Note the reassurance is 'no signal of harm', not a dedicated pregnancy trial.

  • Chua-Gocheco A, Bozzo P, Einarson A. Safety of skin care products during pregnancy. Can Fam Physician 2011. PMC ↗
  • An Overview of the Safety of Skin Care Products During Pregnancy. InfantRisk Center (Texas Tech) ↗
• Vitamin C (ascorbic acid & derivatives)Generally fineLimited evidence

  Considered safe in pregnancy — it is an antioxidant the body already makes and uses, with no contraindication reported for topical use. A good brightening alternative to the ingredients you're skipping. Evidence is reassurance-by-absence rather than a trial.

  • Skin Changes and Safety Profile of Topical Products During Pregnancy (peer-reviewed review). PMC ↗
  • Chua-Gocheco A, Bozzo P, Einarson A. Safety of skin care products during pregnancy. Can Fam Physician 2011. PMC ↗
• Hyaluronic acidGenerally fineLimited evidence

  Considered safe and can be used freely — it is a large humectant molecule native to skin that mainly holds water at the surface, posing minimal systemic risk.

  • Skin Changes and Safety Profile of Topical Products During Pregnancy (peer-reviewed review). PMC ↗
• Arbutin (alpha/beta arbutin)CautionLimited evidence

  A glycosylated form of hydroquinone that slowly releases a small amount of hydroquinone on skin (human data suggest only ~0.07 mol% converts in normal use). Systemic exposure is far lower than hydroquinone itself, but pregnancy-specific data are essentially absent, so it sits in 'probably low risk — use only if your clinician is comfortable', with azelaic acid / vitamin C as better-characterised swaps.

  • Skin Changes and Safety Profile of Topical Products During Pregnancy (peer-reviewed review). PMC ↗
• Kojic acidCautionLimited evidence

  A brightening agent with very low systemic absorption, but no reproductive-safety data — reviews say it is 'still not recommended and further studies are required'. Not flagged as harmful; flagged as unstudied. Prefer better-characterised options during pregnancy.

  • Skin Changes and Safety Profile of Topical Products During Pregnancy (peer-reviewed review). PMC ↗
• Chemical UV filters (oxybenzone / benzophenone-3, avobenzone, octinoxate)CautionLimited evidence

  The concern is theoretical and the evidence limited. Oxybenzone (benzophenone-3) is absorbed (~1–2%, detectable in urine) and has endocrine-disrupting activity in lab and animal studies; a direct effect on human pregnancy is NOT established. Reviews advise using chemical filters with caution and prefer mineral sunscreen (zinc oxide / titanium dioxide) as a simple, well-tolerated swap. Do not stop using sunscreen — just consider a mineral one.

  • Skin Changes and Safety Profile of Topical Products During Pregnancy (peer-reviewed review). PMC ↗
  • Photoprotection in pregnancy: addressing safety concerns and optimizing skin health. PMC ↗
• Mineral UV filters (zinc oxide, titanium dioxide)Generally fineModerate evidence

  The preferred sunscreen filters in pregnancy — these inorganic minerals sit on the skin surface and reflect UV with negligible absorption, and are FDA GRASE. Sun protection matters more than ever because pregnancy raises melasma risk.

  • Skin Changes and Safety Profile of Topical Products During Pregnancy (peer-reviewed review). PMC ↗
• Essential oils (concentrated aromatic oils)CautionLimited evidence

  Blanket claims either way are wrong — this is genuinely under-studied. Essential oils are highly concentrated and some are flagged as possible endocrine disruptors or uterine stimulants (e.g. rosemary, clary sage, sage, wintergreen, camphor, pennyroyal, mugwort). Diluted, low-percentage cosmetic use of common oils is usually tolerated, but for the higher-risk oils and the first trimester, caution and a clinician conversation are sensible.

  • Essential oils during pregnancy. Mayo Clinic Health System ↗

Fungal-acne (Malassezia) checker

• Free fatty acids (C11–C24: lauric, myristic, palmitic, stearic, oleic, linoleic…)AvoidLimited evidence

  Malassezia is a lipophilic yeast that cannot make its own long-chain fatty acids, so it feeds on fatty acids roughly in the C11–C24 range using its own lipases — oleic acid in particular is metabolised into skin-irritating by-products. Free fatty acids in this window are the most consistently reported dietary triggers.

  • Gaitanis G, Magiatis P, Hantschke M, et al. The Malassezia Genus in Skin and Systemic Diseases. Clin Microbiol Rev 2012. PMC ↗
  • Malassezia virulence factors and their role in dermatological disorders (lipase/oleic-acid mechanism). Acta Dermatovenerol APA 2022 ↗
  • Fungal Acne (Malassezia) Ingredient Checker (derm-literature-cited trigger list). SkinSort ↗
• Esters of C12–C24 fatty acids (…stearate, …palmitate, …laurate, …oleate, …myristate)AvoidLimited evidence

  Esters that hydrolyse back into C12–C24 fatty acids can also feed Malassezia — isopropyl palmitate, ethyl oleate and the polysorbate/glyceryl fatty-esters have all fed the yeast in lab studies. This is the single biggest over-flagging bucket: harmless-seeming emulsifiers and thickeners (glyceryl stearate, PEG-100 stearate) get caught. Treat a match as 'worth patch-testing', not 'certainly breaks you out'.

  • Fungal Acne (Malassezia) Ingredient Checker (derm-literature-cited trigger list). SkinSort ↗
  • Malassezia (Pityrosporum) Folliculitis. StatPearls-adjacent review. PMC ↗
• Polysorbates (20, 40, 60, 80)AvoidLimited evidence

  The polysorbate emulsifiers are fatty-acid esters of sorbitan (polysorbate 20/40/60/80 ≈ lauric/palmitic/stearic/oleic) and have been shown to support Malassezia growth in vitro, which is why fungal-acne lists flag them. Real-world rinse-off exposure is brief, so tolerance varies.

  • Fungal Acne (Malassezia) Ingredient Checker (derm-literature-cited trigger list). SkinSort ↗
  • Gaitanis G, Magiatis P, Hantschke M, et al. The Malassezia Genus in Skin and Systemic Diseases. Clin Microbiol Rev 2012. PMC ↗
• Sorbitan esters (sorbitan oleate / stearate / laurate)CautionLimited evidence

  Sorbitan fatty-acid esters (the non-ethoxylated cousins of polysorbates) are commonly flagged for the same reason — the fatty-acid portion can feed the yeast. Evidence is weaker and more indirect than for free fatty acids, so this is a 'caution / patch-test' rather than a firm avoid.

  • Fungal Acne (Malassezia) Ingredient Checker (derm-literature-cited trigger list). SkinSort ↗
• Yeast ferments (Galactomyces, Saccharomyces)CautionLimited evidence

  Fungal ferments such as Galactomyces are commonly avoided by people managing fungal acne — Galactomyces is a potent activator of the aryl-hydrocarbon receptor, a pathway linked to Malassezia-associated skin disease. Note: bacterial ferments (Lactobacillus, Bifidobacterium) are NOT in this group and are generally fine.

  • Gaitanis G, Magiatis P, Hantschke M, et al. The Malassezia Genus in Skin and Systemic Diseases. Clin Microbiol Rev 2012. PMC ↗
  • Fungal Acne (Malassezia) Ingredient Checker (derm-literature-cited trigger list). SkinSort ↗
• Inert hydrocarbons & silicones (mineral oil, petrolatum, dimethicone, squalane)Generally fineLimited evidence

  Not a food source for Malassezia — mineral oil and petrolatum carry no fatty acids, silicones are inert, and squalane's ~C30 chain sits outside the C11–C24 window the yeast uses. Commonly recommended 'safe' occlusives/emollients for fungal-acne-prone skin.

  • Fungal Acne (Malassezia) Ingredient Checker (derm-literature-cited trigger list). SkinSort ↗
  • Malassezia (pityrosporum) folliculitis. DermNet NZ ↗
• Short-chain lipids & humectants (caprylic/capric triglyceride, glycerin, urea)Generally fineLimited evidence

  Caprylic/capric triglyceride (MCT) is built from C8–C10 fatty acids — below the chain length Malassezia consumes — and simple humectants like glycerin and urea are not lipids the yeast can eat. Generally well-tolerated on fungal-acne-prone skin.

  • Fungal Acne (Malassezia) Ingredient Checker (derm-literature-cited trigger list). SkinSort ↗