Peptide Skincare & BeautySkin science and ingredient guides

Ingredient or product comparison

Medik8 C-Tetra™ Advanced Gel-Serum Versus COSRX The 6 Peptide Skin Booster Serum

Medik8 C-Tetra™ Advanced Gel-Serum Versus COSRX The 6 Peptide Skin Booster Serum Detailed comparison of Medik8 C-Tetra™ Advanced Gel-Serum versus COSRX The 6 Peptide Skin Booster Serum. This brightening serum is formulated around Tetrahexyldecyl Ascorbate and

This source-based comparison does not add ratings or recommend a winner.

Medik8 C-Tetra™ Advanced Gel-Serum Versus COSRX The 6 Peptide Skin Booster Serum Detailed comparison of Medik8 C-Tetra™ Advanced Gel-Serum versus COSRX The 6 Peptide Skin Booster Serum. This brightening serum is formulated around Tetrahexyldecyl Ascorbate and Acetyl Glucosamine to brighten dull-looking skin and soften the look of wrinkles. This anti-aging serum is formulated around Niacinamide and Acetyl Hexapeptide-8 to soften the look of wrinkles and strengthen the skin barrier. 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 Dipropylene Glycol Pentylene Glycol Niacinamide Acetyl Hexapeptide-8 Copper Tripeptide-1 Sh-Polypeptide-121 Dipeptide Diaminobutyroyl Benzylamide Diacetate Oligopeptide-68 Palmitoyl Tripeptide-8 Allantoin Serine Alanine Glycine Threonine Arginine Proline Betaine Sodium PCA Sodium Lactate PCA Glutamic Acid Lysine Hcl Dextran Glycine Soja Oil Hydrogenated Lecithin Ammonium Acryloyldimethyltaurate/Vp Copolymer Polyacrylate Crosspolymer-6 Butylene Glycol Adenosine Polyquaternium-51 Disodium EDTA Caprylyl Glycol T-Butyl Alcohol Potassium Sorbate Sodium Oleate Water, Dipropylene Glycol, Glycerin, Pentylene Glycol, 1,2-Hexanediol, Niacinamide, Acetyl Hexapeptide-8, Copper Tripeptide-1, Sh-Polypeptide-121, Dipeptide Diaminobutyroyl Benzylamide Diacetate, Oligopeptide-68, Palmitoyl Tripeptide-8, Allantoin, Sodium Hyaluronate, Acetyl Glucosamine, Serine, Alanine, Glycine, Threonine, Arginine, Proline, Betaine, Sodium PCA, Sodium Lactate, PCA, Glutamic Acid, Lysine Hcl, Tocopherol, Dextran, Glycine Soja Oil, Hydrogenated Lecithin, Ammonium Acryloyldimethyltaurate/Vp Copolymer, Polyacrylate Crosspolymer-6, Butylene Glycol, Xanthan Gum, Ethylhexylglycerin, Adenosine, Polyquaternium-51, Disodium EDTA, Citric Acid, Caprylyl Glycol, T-Butyl Alcohol, Potassium Sorbate, Sodium Oleate These ingredients are found in both products. Ingredients higher up in an ingredient list are typically present in a larger amount. 1,2-Hexanediol is a synthetic liquid and another multi-functional powerhouse. It is a: Humectant, drawing moisture into the skin Emollient, helping to soften skin Solvent, dispersing and stabilizing formulas Preservative booster, enhancing the antimicrobial activity of other preservatives Acetyl Glucosamine is an antioxidant and humectant. It is an amino acid sugar and is naturally found in our skin. The cool thing about this ingredient? It helps the skin produce hyaluronic acid and boost hydration. It also has antioxidant benefits to protect skin cells. When paired with niacinamide, Acetyl Glucosamine has been shown to be effective at reducing discoloration. Citric Acid is an alpha hydroxy acid (AHA) naturally found in citrus fruits like oranges, lemons, and limes. Like other AHAs, citric acid can exfoliate skin by breaking down the bonds that hold dead skin cells together. This helps reveal smoother and brighter skin underneath. However, this exfoliating effect only happens at high concentrations (20%) which can be hard to find in cosmetic products. Due to this, citric acid is usually included in small amounts as a pH adjuster. This helps keep products slightly more acidic and compatible with skin's natural pH. In skincare formulas, citric acid can: While it can provide some skin benefits, research shows lactic acid and glycolic acid are generally more effective and less irritating exfoliants. Most citric acid used in skincare today is made by fermenting sugars (usually from molasses). This synthetic version is identical to the natural citrus form but easier to stabilize and use in formulations. Rosacea skin has a lower threshold for acids generally, with 62.5% of rosacea subjects in one study reacting to lactic acid in a sting test. This is why we mark citric acid as a potential rosacea trigger. However, this ingredient shows up as a pH adjuster or chelator at roughly 0.1-1% in many products. These low levels are unlikely to be an issue for rosacea skin and becomes a potential trigger at exfoliating concentrations (20%). Because everybody's skin is unique, we recommend a patch test if you are unsure. Ethylhexylglycerin is created from glycerin. It is a multitasker ingredient that: The CIR Expert Panel found minimal skin absorption or sensitization of any kind in a safety assessment. Though this ingredient is considered well-tolerated, a small number of cases of allergic dermatitis have been published since 2002. Just be sure to patch test if you are unsure. Industry-reported use ranges from 8% in rinse-off products and 2% in leave-on formulations. 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 shuttl