Peptide Skincare & BeautySkin science and ingredient guides

Ingredient or product comparison

Paula's Choice 25% Vitamin C + Glutathione Clinical Serum Versus SkinBetter Science Alto Defense Serum

Paula's Choice 25% Vitamin C + Glutathione Clinical Serum Versus SkinBetter Science Alto Defense Serum Detailed comparison of Paula's Choice 25% Vitamin C + Glutathione Clinical Serum versus SkinBetter Science Alto Defense Serum. This brightening serum is form

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

Paula's Choice 25% Vitamin C + Glutathione Clinical Serum Versus SkinBetter Science Alto Defense Serum Detailed comparison of Paula's Choice 25% Vitamin C + Glutathione Clinical Serum versus SkinBetter Science Alto Defense Serum. This brightening serum is formulated around Tetrahexyldecyl Ascorbate and Ascorbyl Glucoside to brighten dull-looking skin and fade the look of dark spots. This calming serum is formulated around Glycyrrhiza Glabra Root Extract and Tetrahexyldecyl Ascorbate to calm redness and brighten dull-looking skin. 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 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 Butylene Glycol Propanediol Ethylhexyl Olivate Cetearyl Alcohol Chlorogenic Acids Hydrolyzed Sodium Hyaluronate Lauryl Lactate Dimethyl Isosorbide Glycyrrhiza Glabra Root Extract Benzylidene Dimethoxydimethylindanone Arabidopsis Thaliana Extract Carnosine Camellia Sinensis Leaf Extract Vitis Vinifera Seed Extract Theobroma Cacao Seed Extract Curcuma Longa Root Extract Olea Europaea Fruit Extract Euterpe Oleracea Fruit Extract Trifluoroacetyl Tripeptide-2 Buddleja Officinalis Flower Extract Coffea Arabica Leaf Cell Extract Crocus Sativus Leaf Cell Culture Extract Superoxide Dismutase Ubiquinone Zingiber Officinale Root Extract Ceramide NP Ceramide AP Ceramide EOP Linoleic Acid Linolenic Acid Sea Whip Extract Bisabolol Tocopheryl Acetate Cholesterol Phytosphingosine Jojoba Esters Pentylene Glycol Methyl Gluceth-20 Helianthus Annuus Seed Wax Acacia Decurrens Flower Wax Lecithin Sodium Lauroyl Lactylate Dicetyl Phosphate Propanediol Dicaprylate/Caprate Polyglycerin-3 Ceteth-20 Phosphate Diisostearyl Malate Steareth-2 Acacia Senegal Gum Carbomer Dextran Sodium Hydroxide Citric Acid Disodium EDTA Water, Butylene Glycol, Propanediol, Ethylhexyl Olivate, Cetearyl Alcohol, Chlorogenic Acids, Hydrolyzed Sodium Hyaluronate, Lauryl Lactate, Dimethyl Isosorbide, Glycyrrhiza Glabra Root Extract, Tetrahexyldecyl Ascorbate, Ergothioneine, Benzylidene Dimethoxydimethylindanone Be the first to review These ingredients are found in both products. Ingredients higher up in an ingredient list are typically present in a larger amount. Acrylates/C10-30 Alkyl Acrylate Crosspolymer is a synthetic polymer. It is used to thicken, emulsify, and improve the texture of products. As an emulsifier, it helps stabilize oil-in-water emulsions to give products an elegant feel when applied. It can also form a thin protective film on skin. One study found that a formula using this polymer helped slow down how quickly other ingredients (like DEET) were absorbed through skin. A 2024 study of over 1,300 patients confirmed that sensitization to this ingredient is rare. It is also non-mutagenic and has a clean track record. Ergothioneine is an amino acid found naturally in mushrooms, grains, and meat. It has antioxidant and skin soothing properties. This amino acid helps with: Maintaining DNA stability and cell reproduction Enhances cellular immunity Skin brightening Anti-aging Skin soothing 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 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 st