Mega Thick Shampoo Volumizing Formula

These describe what an ingredient is, not whether it is a problem. The stance marks above are the ratings; these are not.

• common irritantCocamidopropyl Betaine, Propylene Glycol, Diazolidinyl Urea

  • Cocamidopropyl Betaine: A mild cleansing agent, but a recurring patch-test finding, usually traced to leftovers from how it is made. American Contact Dermatitis Society, Allergen of the Year 2004 (Fowler JF Jr, Dermatitis 2004;15(1):3-4).
  • Propylene Glycol: A solvent that shows up in patch-test clinics, more often as irritation than as allergy. American Contact Dermatitis Society, Allergen of the Year 2018 (Jacob SE, Scheman A, McGowan MA, Dermatitis 2018;29(1):3-5).
  • Diazolidinyl Urea: A preservative the FDA lists as a formaldehyde releaser, so formaldehyde-reactive skin can notice it. How much reaches the skin depends on the whole formula, not on this name alone. EU Regulation (EC) 1223/2009, Annex V entry 46, permits diazolidinyl urea as a preservative up to 0,5%. The FDA names it among the "formaldehyde and formaldehyde releasing ingredients" on its Allergens in Cosmetics page (content current 25 February 2022). Annex V preamble point 2, as amended by Commission Regulation (EU) 2022/1181, requires the warning "releases formaldehyde" on any product whose total released formaldehyde exceeds 0,001% (10 ppm). That Regulation states the sensitisation ground itself, so the chain is drawn by the regulator and not by us: recital (2) names the class, "Certain of those preservatives are gradually releasing formaldehyde in order to fulfil a preserving function in the final cosmetic product (so called formaldehyde releasers)", and recital (3) gives the purpose of the warning, "In order to inform consumers sensitised to formaldehyde about the presence of formaldehyde that may trigger an allergic reaction". Recital (1) records that formaldehyde is classified a skin sensitizer (Category 1) in Part 3 of Annex VI to Regulation (EC) 1272/2008.

• undeclared fragrance blendFragrance

  • Fragrance: A blend the label does not itemize, so what is in it cannot be read from the ingredient list. EU Regulation (EC) 1223/2009 permits the collective term "parfum"; the SCCS Opinion on Fragrance Allergens (SCCS/1459/11) reviews the contact-allergy evidence for the substances it can contain.

• retinoidRetinyl Palmitate

  • Retinyl Palmitate: A gentler vitamin A ester that the skin converts to retinol. SCCS Opinion on Vitamin A (Retinol, Retinyl Acetate, Retinyl Palmitate), SCCS/1576/16, which assesses retinyl palmitate by name; EU Regulation (EC) 1223/2009 Annex III entry 376 covers it in the same group as retinol.

• humectantPanthenol

  • Panthenol: A provitamin B5 humectant used in products aimed at irritated and healing skin. On the humectant half: Ferreira VTP, Silva GC, Martin AA, Maia Campos PMBG, "Topical dexpanthenol effects on physiological parameters of the stratum corneum by Confocal Raman Microspectroscopy", Skin Res Technol 2023;29(9):e13317, DOI 10.1111/srt.13317, PMID 37753694, PMCID PMC10504581, open access, Introduction: "As a humectant, it has been shown to retain water more efficiently than other humectants during the last stages of dehydration..." On the soothing half, which that paper does NOT support: Cho YS, Kim HO, Woo SM, Lee DH, "Use of Dexpanthenol for Atopic Dermatitis—Benefits and Recommendations Based on Current Evidence", J Clin Med 2022;11(14):3943, DOI 10.3390/jcm11143943, PMID 35887707, open access, section 3.5: "To facilitate wound healing, dexpanthenol reduces inflammation, and promotes cell proliferation and epithelial remodeling."

• barrier lipidLinoleic Acid

  • Linoleic Acid: An essential fatty acid the skin barrier uses and cannot make for itself. Khnykin D, Miner JH, Jahnsen F, "Role of fatty acid transporters in epidermis", Dermatoendocrinol 2011;3(2):53-61, DOI 10.4161/derm.3.2.14816, open access: "The human body can produce all but two of the fatty acids it needs: linoleic acid (C18:2, n6) and alpha-linolenic acid (C18:3, n3)", and replacing linoleic acid with a non-essential fatty acid "will lead to barrier defects". Feingold and Elias, J Lipid Res 2024: linoleate "is required for the synthesis of a subgroup of acylceramides".

• soothingPanthenol

  • Panthenol: A provitamin B5 humectant used in products aimed at irritated and healing skin. On the humectant half: Ferreira VTP, Silva GC, Martin AA, Maia Campos PMBG, "Topical dexpanthenol effects on physiological parameters of the stratum corneum by Confocal Raman Microspectroscopy", Skin Res Technol 2023;29(9):e13317, DOI 10.1111/srt.13317, PMID 37753694, PMCID PMC10504581, open access, Introduction: "As a humectant, it has been shown to retain water more efficiently than other humectants during the last stages of dehydration..." On the soothing half, which that paper does NOT support: Cho YS, Kim HO, Woo SM, Lee DH, "Use of Dexpanthenol for Atopic Dermatitis—Benefits and Recommendations Based on Current Evidence", J Clin Med 2022;11(14):3943, DOI 10.3390/jcm11143943, PMID 35887707, open access, section 3.5: "To facilitate wound healing, dexpanthenol reduces inflammation, and promotes cell proliferation and epithelial remodeling."