Low pH Scalp Treatment

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

• common irritantPropylene Glycol, Melaleuca Alternifolia Leaf Oil

  • 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).
  • Melaleuca Alternifolia Leaf Oil: An essential oil whose oxidation products carry its sensitising potential; the EU assesses it as a moderate skin sensitiser. SCCS Scientific Opinion on Tea Tree Oil (CAS/EC 68647-73-4 / 285-377-1), SCCS/1681/25, adopted 30 October 2025, which concludes it is a moderate skin sensitiser. It does not set maximum levels of its own: it assesses the concentrations the applicant defended, and finds no concern at 2,0% in shampoo, 1,0% in shower gel, 1,0% in face wash and 0,1% in face cream, for oil conforming to ISO 4730:2017, in adults, in non-sprayable formats. It draws on the earlier SCCP opinions SCCP/1155/08 and SCCP/0843/04 and incorporates their data by reference; it says nothing about their status.

• fragrance materialMenthol

  • Menthol: The cooling component of mint oils, named by the EU as a fragrance substance to be declared on the label. EU Regulation (EC) 1223/2009, Annex III entry 338, inserted by Commission Regulation (EU) 2023/1545: a fragrance substance whose presence must be indicated in the list of ingredients above 0,001% in leave-on and 0,01% in rinse-off products. It is declarable in its OWN right, not by way of any component it carries. The name to look for on a label is "Menthol". The duty applies now. Transition footnote (40) lets stock that does not comply, lawfully placed on the Union market before the 31 July 2026 cut-off, be made available until 31 July 2028.

• rich occlusiveDimethicone

  • Dimethicone: A silicone that forms a film on the surface of the skin without an oily feel. FDA OTC skin protectant monograph, 21 CFR 347.10(g), lists dimethicone as a skin protectant at 1 to 30%.

• humectantPanthenol, Glycerin

  • 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."
  • Glycerin: A humectant, and one of the two ingredients a comparison of moisturiser components found made a significant difference to skin hydration. FDA OTC skin protectant monograph, 21 CFR 347.10(h), lists glycerin as a skin protectant at 20 to 45%. On the humectant half: Jeong CB, Han JY, Cho JC, Suh KD, Nam GW, "Analysis of electrical property changes of skin by oil-in-water emulsion components", Int J Cosmet Sci 2013;35(4):402-410, DOI 10.1111/ics.12059, PMID 23621673, found that "glycerine and urea showed significant skin hydration effects compared with other humectants".

• 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."