Kiehl's Clearly Corrective Dark Spot Solution Versus Paula's Choice 25% Vitamin C + Glutathione Clinical Serum

Kiehl's Clearly Corrective Dark Spot Solution Versus Paula's Choice 25% Vitamin C + Glutathione Clinical Serum Detailed comparison of Kiehl's Clearly Corrective Dark Spot Solution versus Paula's Choice 25% Vitamin C + Glutathione Clinical Serum. This brightening treatment is formulated around 3-O-Ethyl Ascorbic Acid and Salicylic Acid to fade the look of dark spots and brighten dull-looking skin. This brightening serum is formulated around Tetrahexyldecyl Ascorbate and Ascorbyl Glucoside to brighten dull-looking skin and fade the look of dark spots. Water Propylene Glycol Glycerin Alcohol Denat. PEG/PPG/Polybutylene Glycol-8/5/3 Glycerin Hydroxypropyl Tetrahydropyrantriol 3-O-Ethyl Ascorbic Acid PPG-6-Decyltetradeceth-30 Phenoxyethanol Salicylic Acid Xanthan Gum Hydroxyethylcellulose Potassium Hydroxide Citric Acid Sodium Citrate Tocopheryl Acetate Lavandula Angustifolia Oil Disodium EDTA Adenosine Linalool Butylene Glycol Tocopherol Citrus Aurantium Tachibana Peel Extract Paeonia Suffruticosa Root Extract Water, Propylene Glycol, Glycerin, Alcohol Denat., PEG/PPG/Polybutylene Glycol-8/5/3 Glycerin, Hydroxypropyl Tetrahydropyrantriol, 3-O-Ethyl Ascorbic Acid, PPG-6-Decyltetradeceth-30, Phenoxyethanol, Salicylic Acid, Xanthan Gum, Hydroxyethylcellulose, Potassium Hydroxide, Citric Acid, Sodium Citrate, Tocopheryl Acetate, Lavandula Angustifolia Oil, Disodium EDTA, Adenosine, Linalool, Butylene Glycol, Tocopherol, Citrus Aurantium Tachibana Peel Extract, Paeonia Suffruticosa Root Extract Tetrahexyldecyl Ascorbate Dimethicone C9-12 Alkane Ascorbyl Glucoside Silica Pyrus Malus Fruit Extract Hydrogenated Lecithin Polyglyceryl-6 Polyricinoleate Acrylates/C10-30 Alkyl Acrylate Crosspolymer Oryza Sativa Bran Extract Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer Cetyl Alcohol Caprylyl Glycol Lysine Carboxymethyl Cysteinate Coco-Caprylate/Caprate Glutathione Sodium Phytate Hexylene Glycol Ethylhexylglycerin Helianthus Annuus Seed Extract Urea Mannitol Caprylic/Capric Triglyceride Sodium PCA Rosmarinus Officinalis Leaf Extract Polysorbate 60 Sorbitan Isostearate Trehalose Ascorbic Acid Glucose Vanilla Planifolia Fruit Extract Polyquaternium-51 Ergothioneine Triacetin Sodium Hyaluronate Water, Tetrahexyldecyl Ascorbate, Dimethicone, Glycerin, C9-12 Alkane, Ascorbyl Glucoside, Silica, Pyrus Malus Fruit Extract, Hydrogenated Lecithin, Polyglyceryl-6 Polyricinoleate, Acrylates/C10-30 Alkyl Acrylate Crosspolymer, Xanthan Gum, Oryza Sativa Bran Extract, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Cetyl Alcohol, Caprylyl Glycol, Lysine Carboxymethyl Cysteinate, Coco-Caprylate/Caprate, Tocopherol, Glutathione, Sodium Citrate, Sodium Phytate, Hexylene Glycol, Ethylhexylglycerin, Helianthus Annuus Seed Extract, Urea, Mannitol, Caprylic/Capric Triglyceride, Sodium PCA, Rosmarinus Officinalis Leaf Extract, Polysorbate 60, Sorbitan Isostearate, Trehalose, Ascorbic Acid, Glucose, Vanilla Planifolia Fruit Extract, Polyquaternium-51, Ergothioneine, Triacetin, Sodium Hyaluronate, Phenoxyethanol These ingredients are found in both products. Ingredients higher up in an ingredient list are typically present in a larger amount. Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum. Topically, glycerin does several things at once: Your skin makes glycerin on its own (mostly from sebaceous oil breakdown) and shuttles it to your outermost layer of skin, or your epidermis, via aquaporin-3. Aquaporin-3 is a transporter that is essential for normal skin hydration, elasticity, and repair. Interestingly, mice lacking in AQP3 have dry and less elastic skin that can be fully corrected with glycerin. This ingredient is non-irritating, plays well with almost every ingredient, and works across all skin types. Typical use is anywhere between 3-10% but can go up to 79% in some leave-on products. Just know very high concentrations (>40%) can feel tacky in low humidity. Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine. Phenoxyethanol is one of the most widely used preservatives in skincare (and for good reason!). It has a large spectrum of antimicrobial activity and especially effective bacteria, yeast, and mold while only having a weak effect on your skin's natural microbiome. On a cellular level, it disrupts the cell membranes of microbes by poking holes that make the cell leak. This shuts down the chemical reactions the microbe needs to make energy so it can no longer survive. Another perk of this ingredient is that it stays functional across a wide pH range (3-10). You'll often see it paired with boosters like Ethylhexylglycerin; one study showed that a 1:9 ratio of Ethylhexylglycerin to Phenoxyethanol damages bacterial membranes as effectively as doubling the Phenoxyethanol concentration on its own. Typical use concentrations range from 0.3-1% depending on the formula, and this ingredient is capped at 1% int the EU. Safety-wise, the fear mongering does not hold up to the evidence. The EU's Scientific Committee on Consumer Safety and FDA consider it safe as a preservative at up to 1%, including for children of all ages. Adverse systemic effects only showed up in animal studies at exposures roughly 200x higher than what people get from cosmetics. And despite its very widespread use, this ingredient is a rare sensitizer and allergic reactions are uncommon. Sodium Citrate is the sodium salts of citric acid. In skincare, it is used to alter pH levels and acts as a preservative. Its main functions are to maintain the pH of a product and neutralize metal ions. The acidity of our skin is maintained by our glands and skin biome; normal pH level of skin is slightly acidic (~4.75-5.5). Being slightly acidic allows our skin to create an "acid mantle". This acid mantle is a thin barrier that protects our skin from bacteria and contaminants. Tocopherol is a fat-soluble antioxidant known as Vitamin E. 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