Kiehl's Powerful-Strength Vitamin C Serum Versus Paula's Choice C5 Super Boost Eye Cream

Kiehl's Powerful-Strength Vitamin C Serum Versus Paula's Choice C5 Super Boost Eye Cream Detailed comparison of Kiehl's Powerful-Strength Vitamin C Serum versus Paula's Choice C5 Super Boost Eye Cream. This anti-aging serum is formulated around Ascorbic Acid and Ascorbyl Glucoside to soften the look of wrinkles and brighten dull-looking skin. This brightening eye moisturizer is formulated around Ascorbyl Glucoside and 3-O-Ethyl Ascorbic Acid to brighten dull-looking skin and soften the look of wrinkles. Propylene Glycol Dimethicone Glycerin Ascorbic Acid Ethylhexyl Palmitate Cetyl PEG/PPG-10/1 Dimethicone Dimethicone Crosspolymer Ascorbyl Glucoside Cyclohexasiloxane Hydroxyethylpiperazine Ethane Sulfonic Acid Lauroyl Lysine Acrylonitrile/Methyl Methacrylate/Vinylidene Chloride Copolymer Polysilicone-11 Adenosine Hydrolyzed Hyaluronic Acid Limonene Isobutane Citrus Aurantium Dulcis Peel Oil Citrus Limon Peel Oil Citral Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate Propylene Glycol, Dimethicone, Glycerin, Ascorbic Acid, Ethylhexyl Palmitate, Cetyl PEG/PPG-10/1 Dimethicone, Dimethicone Crosspolymer, Ascorbyl Glucoside, Cyclohexasiloxane, Hydroxyethylpiperazine Ethane Sulfonic Acid, Lauroyl Lysine, Acrylonitrile/Methyl Methacrylate/Vinylidene Chloride Copolymer, Polysilicone-11, Adenosine, Hydrolyzed Hyaluronic Acid, Limonene, Isobutane, Citrus Aurantium Dulcis Peel Oil, Citrus Limon Peel Oil, Citral, Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate Water Dicaprylyl Carbonate Triheptanoin 3-O-Ethyl Ascorbic Acid Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer Arachidyl Alcohol Cetearyl Alcohol C13-15 Alkane Ascorbyl Palmitate Sh-Polypeptide-121 Acetyl Hexapeptide-8 Hyaluronic Acid Zerumbone Bacillus Ferment Tocopherol Tocopheryl Acetate Butyrospermum Parkii Butter Unsaponifiables Oryza Sativa Bran Extract Rosmarinus Officinalis Leaf Extract Helianthus Annuus Seed Oil Helianthus Annuus Seed Extract Hydrogenated Lecithin Cetearyl Olivate Sorbitan Olivate Behenyl Alcohol Arachidyl Glucoside Propanediol Butylene Glycol Cetyl Alcohol Sodium Phytate Sodium Citrate Citric Acid Sodium Metabisulfite Phenoxyethanol Caprylyl Glycol Ethylhexylglycerin Hexylene Glycol Sodium Hydroxide Water, Dicaprylyl Carbonate, Glycerin, Triheptanoin, Ascorbyl Glucoside, 3-O-Ethyl Ascorbic Acid, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Arachidyl Alcohol, Cetearyl Alcohol, C13-15 Alkane, Ascorbyl Palmitate, Sh-Polypeptide-121, Acetyl Hexapeptide-8, Hyaluronic Acid, Zerumbone, Bacillus Ferment, Tocopherol, Tocopheryl Acetate, Butyrospermum Parkii Butter Unsaponifiables, Oryza Sativa Bran Extract, Rosmarinus Officinalis Leaf Extract, Helianthus Annuus Seed Oil, Helianthus Annuus Seed Extract, Hydrogenated Lecithin, Cetearyl Olivate, Sorbitan Olivate, Behenyl Alcohol, Arachidyl Glucoside, Propanediol, Butylene Glycol, Cetyl Alcohol, Sodium Phytate, Sodium Citrate, Citric Acid, Sodium Metabisulfite, Phenoxyethanol, Caprylyl Glycol, Ethylhexylglycerin, Hexylene Glycol, Sodium Hydroxide These ingredients are found in both products. Ingredients higher up in an ingredient list are typically present in a larger amount. Ascorbyl Glucoside (AA-2G) is one of the most stable vitamin C derivatives out there. It's made by attaching a glucose molecule to ascorbic acid; this glucose "cap" shields the vitamin C from air, light, heat, and metal ions that normally cause pure ascorbic acid to oxidize. Once on your skin, the enzyme alpha-glucosidase snips off the glucose and gradually releases active ascorbic acid right where it's needed. Basically, it behaves like a slow-release pro-vitamin C with less of a stinging that high-strength ascorbic acid can cause. The research supports the classic vitamin C benefits as well. In lab and human studies, AA-2G slowed down the skin's production of melanin (the pigment behind dark spots) and helped shield skin cells against sun damage better than ascorbyl phosphate. These studies also showed AA-2G released vitamin C over a longer period. A frequently cited manufacturer trial found that a 2% AA-2G face cream significantly improved wrinkle depth and skin roughness after 45 days. And in 2009, a clinical trial showed it meaningfully lightened dark patches on the gums compared to a placebo. There's also collagen-synthesis support (since vitamin C is a required cofactor for that) and an antioxidant effect too. Typical usage is usually between 0.5-5% and most studies/products land around 2%. AA-2G performs best when formulated at a mildly acidic pH (~5-7) which is much gentler than the pH that pure vitamin C demands (~2.5-3.5). Just one thing worth knowing: the in-skin conversation rate is only about 55-60% by weight. So a 5% AA-2G product delivers roughly 2.75-3% of actual active vitamin C. On top of that, skin absorption is relatively low because the ingredient is water-soluble. 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.