Olay Vitamin C + Peptide 24 Brightening Serum Versus COSRX The Vitamin C 23 Serum

Olay Vitamin C + Peptide 24 Brightening Serum Versus COSRX The Vitamin C 23 Serum Detailed comparison of Olay Vitamin C + Peptide 24 Brightening Serum versus COSRX The Vitamin C 23 Serum. This brightening serum is formulated around Niacinamide and Lactic Acid to brighten dull-looking skin and refine skin texture. This brightening serum is formulated around Ascorbic Acid and 3-O-Ethyl Ascorbic Acid to brighten dull-looking skin and fade the look of dark spots. Water Glycerin Dimethicone Niacinamide Lactic Acid Polyacrylate Crosspolymer-6 3-O-Ethyl Ascorbic Acid Palmitoyl Pentapeptide-4 Panthenol Trehalose PEG-11 Methyl Ether Dimethicone Sodium Lactate Sodium Benzoate Parfum Hydroxylauric Acid Ascorbic Acid Avena Sativa Peptide Water, Glycerin, Dimethicone, Niacinamide, Lactic Acid, Polyacrylate Crosspolymer-6, 3-O-Ethyl Ascorbic Acid, Palmitoyl Pentapeptide-4, Panthenol, Trehalose, PEG-11 Methyl Ether Dimethicone, Sodium Lactate, Sodium Benzoate, Parfum, Hydroxylauric Acid, Ascorbic Acid, Avena Sativa Peptide Ascorbic Acid 23% Propanediol Tromethamine Squalane Caffeine Sodium Chloride Sodium Hyaluronate Sodium Sulfite Disodium EDTA Glutathione Adenosine Acetyl Glucosamine Gardenia Florida Fruit Extract Allantoin Dextrin Tocotrienols Tocopherol Elaeis Guineensis Oil Butylene Glycol Arginine Pentylene Glycol Alcohol Denat. Helianthus Annuus Seed Oil Glycyrrhiza Glabra Root Extract Methyl Trimethicone Carthamus Tinctorius Seed Oil Camellia Japonica Seed Oil Daucus Carota Sativa Root Extract Beta-Carotene Water, Ascorbic Acid 23%, Propanediol, Dimethicone, Tromethamine, Panthenol, 3-O-Ethyl Ascorbic Acid, Squalane, Caffeine, Sodium Chloride, Sodium Hyaluronate, Sodium Sulfite, Disodium EDTA, Glutathione, Adenosine, Acetyl Glucosamine, Gardenia Florida Fruit Extract, Allantoin, Dextrin, Tocotrienols, Tocopherol, Elaeis Guineensis Oil, Butylene Glycol, Arginine, Niacinamide, Pentylene Glycol, Alcohol Denat., Helianthus Annuus Seed Oil, Glycyrrhiza Glabra Root Extract, Methyl Trimethicone, Carthamus Tinctorius Seed Oil, Camellia Japonica Seed Oil, Daucus Carota Sativa Root Extract, Beta-Carotene These ingredients are found in both products. Ingredients higher up in an ingredient list are typically present in a larger amount. 3-O-Ethyl Ascorbic Acid is one of the most popular "stable" vitamin C derivatives in skincare. Plain ascorbic acid is fantastic but notoriously fragile; it browns, oxidizes, and loses potency fast. So attaching an ethyl group to the third carbon of the molecule gives it some cool perks: In a formula, it does the 3 classic vitamin C jobs: it acts as an antioxidant, helps brighten skin tone by inhibiting tyrosinase, and supports collagen. The evidence is reasonably solid for a cosmetic ingredient; Liao and colleagues (2018) showed it's significantly more stable than ascorbic acid while still being effective. A 2021 study by Zerbinati and colleagues tested a serum with 30% 3-O-ethyl-l-ascorbic acid and 1% lactic acid significantly increased collagen production, reduced UVB-induced DNA damage, and decreased melanin on a reconstructed pigmented skin model. Typical real world usage sits around 0.5-5% (and 1-2% is common for daily serums). Amounts up to 30% have been shown to be non-irritating on human skin samples, but two isolated cases reported allergic contact dermatitis so a patch test is sensible if you have reactive skin. Ascorbic Acid is is pure Vitamin C and is the biologically active form used directly by skin. Not only is vitamin C great for your overall health and immune system, but it also has plenty of benefits for your skin. It is best supported by academic literature for: Topical vitamin C has been shown to help neutralize oxidative stress from UV and pollution, helping to improve photoaging and hyperpigmentation when used consistently. One clinical study found that using 5% topical vitamin C for six months improved signs of photodamaged skin, both on the surface and in the deeper structural layers of the skin. While vitamin C doesn’t replace sunscreen, studies show it can boost photoprotection when combined with Vitamin E and ferulic acid. These two ingredients help improve stability and protective effects. The big downside of this ingredient is formulation difficulty. Vitamin C is prone to oxidation and doesn't penetrate the skin unless formulated correctly. Research found that vitamin C absorbs into the skin best at a low pH (< 3.5) with about 20% being the upper limit for effective absorption. Skin levels can saturate after repeated application; this means your skin won’t keep absorbing more once it’s full of vitamin C. This is why more isn’t always better with vitamin C and why very high concentrations don’t necessarily give extra benefits. Ascorbic acid generally works well with many skincare ingredients but can be irritating when combined with other active ingredients. Strong oxidizing acne treatments like benzoyl peroxide can reduce the effectiveness of vitamin C if they are used at the same time; they are often recommended for use at different times of day. Read more about other types of Vitamin C: