Formula · 7.9

Brand · 5.7

Ducray · salicylic acid + ichthyol · France

Ducray Kertyol PSO

Ducray Kertyol PSO
7.9

LabReadAI label score

How the score is calculated
  • Actives and evidence0.8Actives with strong evidence: 0 of 2
  • Completeness for the purpose0.8For “dandruff and itchy scalp” — 75 %; piroctone olamine; nasturtium extract; could be added without conflict: piroctone olamine, nasturtium extract; a broad formula across 7 purposes
  • Cleansing base0.8Mild surfactants: sodium lauroamphoacetate; irritation potential of the base — 20 % of SLS
  • Tolerance0.9Rinse-off product; debatable groups: fragrance and its allergens (skin test positive in 13 of 100 tested)
  • adults
  • dry skin
  • colour-treated hair
  • pregnancysalicylates — ask a doctor
  • sensitive skinstart at 0.5 %
  • atopic skinfragrance is a common trigger
Free from:
  • alcohol (alcohol denat) · by the listthe list has no ingredient of the “denatured alcohol” group — evaporates fast and degreases; frequent contact can dry the skin — a tolerance question, not a regulatory one; does not clog pores
  • sulfates (SLS/SLES) · by the listthe list has no ingredient of the “ammonium laureth sulfate (ALES), ammonium lauryl sulfate (ALS), sodium coco-sulfate, sodium laureth sulfate (SLES), sodium lauryl sulfate (SLS), sodium myreth sulfate, TEA-lauryl sulfate” group — a cleansing surfactant from the sulfate family but with an ethoxylated chain: it cleanses more gently than lauryl sulfate. Still not for those looking for a sulfate-free product.
  • formaldehyde releasers · by the listthe list has no ingredient of the “formaldehyde releasers” group — preservatives that slowly release formaldehyde; allowed at low levels but a frequent cause of contact allergy
  • isothiazolinones (MIT/MCI) · by the listthe list has no ingredient of the “isothiazolinone preservatives (MIT/MCI)” group — preservatives; banned in EU leave-on products and limited in rinse-off (0.0015%) — a frequent cause of contact allergy
  • parabens · by the listthe list has no ingredient of the “parabens” group — preservatives; methyl- and ethylparaben are recognised as safe at permitted levels, propyl- and butyl- are limited by the EU to 0.14 %; a frequent buyer question rather than proven harm
  • mineral oils and petrolatum · by the listthe list has no ingredient of the “petrolatum and mineral oils” group — purified cosmetic-grade petroleum products: form a protective barrier film; safety is established, a preference question; 0–2 of 5 (depends on the raw-material source), cosmetic white oil per DiNardo (2005) is non-comedogenic
  • soap · by the listthe list has no ingredient of the “potassium soap (potassium cocoate), plant soap base (sodium palmate, sodium cocoate), tallow soap base (sodium tallowate)” group — liquid soap: fatty acids boiled with alkali. It cleanses well, but its acidity is around 9-10 against 5 for skin, which is why it often leaves tightness. The product is rinsed off, so the question is tolerance.
  • silicones · by the listthe list has no ingredient of the “silicones” group — form a smooth film and shine; inert and not absorbed — a preference question, not a safety one
  • gelatin in the coating · by the listthe list has no ingredient of the “vegetarian coating” group — a plant-based tablet coating instead of gelatin; it keeps moisture out and makes swallowing easier
  • toning dyes · by the listthe list has no ingredient of the “violet toning dyes” group — direct dyes that settle on the hair surface and cancel the yellow cast of blonde; they wash out in 1–3 washes and leave a lilac tint if left too long; HC Blue 2 and Disperse Violet 1 are known contact allergens of hair dyes
  • tar · by the listthe list has no ingredient of the “wood (birch) tar” group — a traditional remedy for dandruff and itching with a sharp smell; it reduces flaking, but can irritate a sensitive scalp and dries the hair
What for: Dandruff is the Malassezia fungus plus accelerated flaking. You need an antifungal active (piroctone olamine, zinc pyrithione, ketoconazole) and a mild cleansing base; results come after 2–4 weeks of regular washing.
When:
  • when washing, rinsed off
  • evening
on skin — in the evening, starting 2–3 times a week; in a shampoo — at every wash, leave for 2–3 minutes
When to expect an effect: pores, blackheads — 4–8 weeks; less breakage — after a few applications
What is normal: mild dryness and flaking in the first weeks; weighs fine hair down and looks greasy; on the face — comedones

Ingredients — 14 components · 2 work

What works: 2 of 14 ingredients: salicylic acid, coconut oil. Dandruff is the Malassezia fungus plus accelerated flaking. You need an antifungal active (piroctone olamine, zinc pyrithione, ketoconazole) and a mild cleansing base; results come after 2–4 weeks of regular washing.

Strengths: tolerance

What lowers the score: actives and evidence: actives with strong evidence: 0 of 2; completeness for the purpose: for “dandruff and itchy scalp” — 75 %; cleansing base: mild surfactants: sodium lauroamphoacetate

Questions: fragrance and its allergens: fragrance — the fragrance and its aromatic components; the EU requires 26 of them to be listed separately — matters to people allergic to fragrance, does not affect how the product works

  • WATER (AQUA base: coating, fillers · water — the solvent and base; listed first because there is more of it than anything else; in supplements — part of the capsule shell
  • COCOS NUCIFERA (COCONUT) OIL (COCOS NUCIFERA OIL works · the active ingredient — what the product is for; form: oil
  • SODIUM TRIDECETH SULFATE label wording · an allergen (sodium (salt)) — matters when limiting salt, for example with blood pressure; the label says it is absent
  • SODIUM LAUROAMPHOACETATE base: coating, fillers · an amphoteric surfactant from tear-free baby shampoos: it cleanses gently and barely stings the eyes.
  • COCAMIDE MIPA base: coating, fillers · a thickener and foam booster from coconut oil: it barely cleanses on its own, it makes the foam denser.
  • GLYCERIN base: coating, fillers · a humectant: coats the tablet, holds moisture in creams and shampoos; does not clog pores
  • SODIUM CHLORIDE base: coating, fillers · tune the acidity and texture; salt is a common shampoo thickener
  • SALICYLIC ACID works · the active ingredient — what the product is for; form: salicylic acid
  • 1,2-HEXANEDIOL base: coating, fillers · a solvent and humectant with antimicrobial action: it helps the product keep without classic preservatives.
  • CAPRYLYL GLYCOL base: coating, fillers · a humectant that also holds bacteria back, which is why it often replaces part of the preservative.
  • CICHORIUM INTYBUS (CHICORY) ROOT EXTRACT base: coating, fillers · plant and algae extracts and floral waters: flavouring and marketing components — at these shares there is no proven effect on the skin; rare reactions in people allergic to that particular plant
  • FRAGRANCE (PARFUM questions · the fragrance and its aromatic components; the EU requires 26 of them to be listed separately — matters to people allergic to fragrance, does not affect how the product works
  • ICTASOL base: coating, fillers · holds back the fungus and the flaking of the scalp
  • PENTYLENE GLYCOL base: coating, fillers · humectants and solvents — hold water and help actives dissolve
  • TRIPTERYGIUM WILFORDII CALLUS EXTRACT base: coating, fillers · softens the skin and helps it hold water — the most common role in creams

Ducray Kertyol PSO is a product whose active ingredient is salicylic acid (bha) + coconut oil. The concentration is not declared, but the active sits above the 1 % line in the list — a working share is likely. The effect is moderately supported: salicylic acid (bha), coconut oil. The formula has 14 ingredients, 2 of which do the work; the rest is the formula base. Worth noting: FRAGRANCE (PARFUM (the fragrance and its aromatic components; the EU requires 26 of them to be listed separately — matters to people allergic to fragrance, does not affect how the product works). Dandruff is the Malassezia fungus plus accelerated flaking. You need an antifungal active (piroctone olamine, zinc pyrithione, ketoconazole) and a mild cleansing base; results come after 2–4 weeks of regular washing. By the list, no alcohol (alcohol denat), sulfates (SLS/SLES), formaldehyde releasers, isothiazolinones (MIT/MCI), parabens, mineral oils and petrolatum, soap, silicones, gelatin in the coating, toning dyes, tar. Suitable for: adults, dry skin, colour-treated hair. pregnancy, sensitive skin, atopic skin — ask a doctor. acne-prone face, fragrance allergy — not without a doctor. Use: on skin — in the evening, starting 2–3 times a week; in a shampoo — at every wash, leave for 2–3 minutes. When to expect an effect: pores, blackheads — 4–8 weeks. Label score — 7.9 out of 10 (actives with strong evidence: 0 of 2; for “dandruff and itchy scalp” — 75 %; piroctone olamine; nasturtium extract; could be added without conflict: piroctone olamine, nasturtium extract; a broad formula across 7 purposes; mild surfactants: sodium lauroamphoacetate; irritation potential of the base — 20 % of sls; rinse-off product; debatable groups: fragrance and its allergens (skin test positive in 13 of 100 tested)). Per the pack: for external use, avoid contact with the eyes. A restatement of the label, not an assessment.

Who it does not suit

  • acne-prone facecomedogenic
  • fragrance allergyrisk of reaction

When to stop: burning, persistent redness — stop; breakouts on the face or scalp — stop

Per the maker's leaflet: Per the pack: for external use, avoid contact with the eyes. A restatement of the label, not an assessment.

Is this product right for your hair?

The score describes the formula, not your hair: a sulfate shampoo suits an oily scalp and fails a dry, sensitive one. Tell us about your hair, scalp and the problem — shedding, dandruff, oiliness, dryness — and we will build a routine and say whether this product suits you.

Hair care matchDecode my tests

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