Barefaced Hydrating Lotion

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

  • 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).

• 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%.

• humectantGlycerin, Sodium Hyaluronate

  • 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".
  • Sodium Hyaluronate: A humectant that holds a large amount of water at the skin surface. Chylińska N, Maciejczyk M, "Hyaluronic Acid and Skin: Its Role in Aging and Wound-Healing Processes", Gels 2025;11(4):281, DOI 10.3390/gels11040281, PMID 40277717, open access: hyaluronic acid's "high osmotic activity and anionic structure enable it to bind large amounts of water", and "sodium and potassium hyaluronate are widely used in moisturizing products". The same review notes that high-molecular-weight hyaluronic acid does not penetrate the deeper layers.

• barrier lipidCeramide AP, Cholesterol

  • Ceramide AP: One of the lipid families the skin barrier is actually built from. Feingold KR and Elias PM, "The role of ceramides in the disruption of the cutaneous permeability barrier, a common manifestation of skin disorders", J Lipid Res 2024;65(8):100593, DOI 10.1016/j.jlr.2024.100593, open access: the barrier lipid matrix "by weight is approximately 50% ceramides, 25% cholesterol, and 15% free fatty acids".
  • Cholesterol: One of the three lipid classes that make up the skin barrier, alongside ceramides and fatty acids. Feingold KR and Elias PM, J Lipid Res 2024, open access: the barrier lipid matrix "by weight is approximately 50% ceramides, 25% cholesterol, and 15% free fatty acids". Corroborated by Wertz PW, "Roles of Lipids in the Permeability Barriers of Skin and Oral Mucosa", Int J Mol Sci 2021;22(10):5229, DOI 10.3390/ijms22105229, PMID 34063352.

• soothingNiacinamide

  • Niacinamide: A vitamin B3 form that supports the skin barrier and has anti-inflammatory activity; it turns up in products aimed at acne, rosacea and eczema. Camillo L, Zavattaro E, Savoia P, "Nicotinamide: A Multifaceted Molecule in Skin Health and Beyond", Medicina (Kaunas) 2025;61(2):254, DOI 10.3390/medicina61020254, PMID 40005371, open access: it "is extensively used in ... the treatment of dermatological conditions such as blistering diseases, atopic dermatitis, rosacea, and acne vulgaris", and contributes to reducing inflammation. On the acne evidence specifically: Liu H, Yu H, Xia J, Liu L, Liu GJ, Sang H, Peinemann F, "Topical azelaic acid, salicylic acid, nicotinamide, sulphur, zinc and fruit acid (alpha-hydroxy acid) for acne", Cochrane Database Syst Rev 2020;5:CD011368, DOI 10.1002/14651858.CD011368.pub2, PMID 32356369, records "low-quality evidence" for every nicotinamide comparison it could pool, and none of its four nicotinamide studies measured the physician global assessment at all.