Medik8 C-Tetra™ Advanced Gel-Serum Versus Allies of Skin 20% Vitamin C Brighten + Firm Serum

Medik8 C-Tetra™ Advanced Gel-Serum Versus Allies of Skin 20% Vitamin C Brighten + Firm Serum Detailed comparison of Medik8 C-Tetra™ Advanced Gel-Serum versus Allies of Skin 20% Vitamin C Brighten + Firm Serum. This brightening serum is formulated around Tetrahexyldecyl Ascorbate and Acetyl Glucosamine to brighten dull-looking skin and soften the look of wrinkles. This brightening serum is formulated around 3-O-Ethyl Ascorbic Acid and Glutathione to brighten dull-looking skin. Water Tetrahexyldecyl Ascorbate Isododecane Propanediol Acetyl Glucosamine Squalane Tocopherol Acetyl Zingerone Camellia Sinensis Leaf Hydroxyacetophenone Sodium Hyaluronate Cellulose Avena Sativa Kernel Extract Glycerin Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer Citrus Grandis Peel Oil Sucrose Stearate Tetrasodium Glutamate Diacetate Ethylhexylglycerin Acrylates/C10-30 Alkyl Acrylate Crosspolymer Xanthan Gum Sodium Benzoate Cellulose Gum 1,2-Hexanediol Polysorbate 60 Sorbitan Isostearate Citric Acid Phenoxyethanol Citral Linalool Limonene Water, Tetrahexyldecyl Ascorbate, Isododecane, Propanediol, Acetyl Glucosamine, Squalane, Tocopherol, Acetyl Zingerone, Camellia Sinensis Leaf, Hydroxyacetophenone, Sodium Hyaluronate, Cellulose, Avena Sativa Kernel Extract, Glycerin, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Citrus Grandis Peel Oil, Sucrose Stearate, Tetrasodium Glutamate Diacetate, Ethylhexylglycerin, Acrylates/C10-30 Alkyl Acrylate Crosspolymer, Xanthan Gum, Sodium Benzoate, Cellulose Gum, 1,2-Hexanediol, Polysorbate 60, Sorbitan Isostearate, Citric Acid, Phenoxyethanol, Citral, Linalool, Limonene 3-O-Ethyl Ascorbic Acid Benzimidazole Diamond Amidoethyl Urea Carbamoyl Propyl Polymethylsilsesquioxane Dimethyl Isosorbide Helianthus Annuus Seed Wax Polyglyceryl-10 Tristearate Ethoxydiglycol Dicaprylyl Ether Caprylyl Glycol Citrus Aurantium Dulcis Callus Culture Extract Glutathione Acetyl Cysteine Dimethylmethoxy Chromanol Ergothioneine Gluconolactone Leuconostoc/Radish Root Ferment Filtrate Silica Calcium Gluconate Propanediol, Glycerin, 3-O-Ethyl Ascorbic Acid, Benzimidazole Diamond Amidoethyl Urea Carbamoyl Propyl Polymethylsilsesquioxane, Dimethyl Isosorbide, Helianthus Annuus Seed Wax, Polyglyceryl-10 Tristearate, Ethoxydiglycol, Dicaprylyl Ether, Water, Caprylyl Glycol, Citrus Aurantium Dulcis Callus Culture Extract, Glutathione, Acetyl Cysteine, Dimethylmethoxy Chromanol, Ergothioneine, Tocopherol, Gluconolactone, Leuconostoc/Radish Root Ferment Filtrate, Xanthan Gum, Silica, Sodium Benzoate, Calcium Gluconate, 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. Propanediol is an all-star ingredient. It softens, hydrates, and smooths the skin. It’s often used to: Propanediol is not likely to cause sensitivity and considered safe to use. It is derived from corn or petroleum with a clear color and no scent. Sodium Benzoate is a preservative. It's used in both cosmetic and food products to inhibit the growth of mold and bacteria. It is typically produced synthetically. Both the US FDA and EU Health Committee have approved the use of sodium benzoate. In the US, levels of 0.1% (of the total product) are allowed. Sodium benzoate work