Skin science article
Paula's Choice 25% Vitamin C + Glutathione Clinical Serum Versus Dermalogica Biolumin C Serum
Paula's Choice 25% Vitamin C + Glutathione Clinical Serum Versus Dermalogica Biolumin C 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 brigh
Paula's Choice 25% Vitamin C + Glutathione Clinical Serum Versus Dermalogica Biolumin C 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 brightening serum is formulated around Lactic Acid and Palmitoyl Tripeptide-5 to brighten dull-looking skin and soften the look of wrinkles.
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
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
Ethoxydiglycol
Lactic Acid
Salvia Hispanica Seed Extract
Palmitoyl Tripeptide-5
Sophora Japonica Flower Extract
Ascorbyl Methylsilanol Pectinate
Dipotassium Glycyrrhizate
Aminopropyl Ascorbyl Phosphate
Polyacrylate-13
Propanediol
Citrus Grandis Peel Oil
Helianthus Annuus Seed Oil
Polyisobutene
Methylpropanediol
Carrageenan
Pentylene Glycol
Glyceryl Polyacrylate
Tetrasodium Glutamate Diacetate
Polysorbate 20
Limonene
Sodium Hydroxide
Water, Glycerin, Butylene Glycol, Ethoxydiglycol, Lactic Acid, Salvia Hispanica Seed Extract, Sodium PCA, Palmitoyl Tripeptide-5, Sophora Japonica Flower Extract, Ascorbyl Methylsilanol Pectinate, Sodium Hyaluronate, Tocopherol, Dipotassium Glycyrrhizate, Aminopropyl Ascorbyl Phosphate, Trehalose, Polyacrylate-13, Propanediol, Citrus Grandis Peel Oil, Helianthus Annuus Seed Oil, Polyisobutene, Methylpropanediol, Carrageenan, Pentylene Glycol, Glyceryl Polyacrylate, Caprylyl Glycol, Ethylhexylglycerin, Tetrasodium Glutamate Diacetate, Xanthan Gum, Polysorbate 20, Limonene, Sodium Hydroxide, Phenoxyethanol
Reviews
Alternatives
Ingredients Explained
These ingredients are found in both products.
Ingredients higher up in an ingredient list are typically present in a larger amount.
Caprylyl Glycol is a humectant, skin conditioner, emollient, and preservative booster derived from either caprylic acid or synthetically created.
Typical use levels vary from 0.3-1% as a preservative booster and go up to 2% to condition skin.
Because it is not a free-fatty acid, this ingredient is fungal acne safe (there's nothing for Malassezia to feed on).
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 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.
Sodium Hyaluronate is the salt form of hyaluronic acid. It is a long sugar chain that is naturally found in your skin, joints, and connective tissue that maintains hydration and elasticity.
In skincare, it works as a humectant. It pulls water from the environment and deeper layers of skin and binds it to the surface.
Interestingly, the size of the molecule affects its behavior:
Some clinical evidence links low molecular weight versions to improved wrinkle depth, elasticity, anti-inflammatory effects, and barrier repair.
Many serums use a blend of both weights so you can get surface hydration plus longer-lasting and deeper effects.
You'll typically see concentrations between 0.1-2% for this ingredient.
Sodium PCA (the salt of PCA) is one of the most well-established humectants in skincare.
Why is it so special? Your skin already makes it naturally; it's a natural component of your skin's Natural Moisturizing Factor (NMF), or the mix of water-binding compounds inside your skin cells that keeps things soft and hydrated.
As a cosmetic ingredient, it grabs water and holds it in the upper layers of skin to smooth roughness and ease dehydration.
There's some clinical support for the NMF approach with a study showing that a cream built to mimic the skin's NMF significantly boosted hydration.
Safety-wise, this ingredient non-irritating, non-comedogenic, and non-phototoxic in testing, with minimal skin absorption.
It also works really well with other hydrators like glycerin or hyaluronic acid, and typical usage is somewhere between 0.2-4%.
Tocopherol is a fat-soluble antioxidant known as Vitamin E.
You'll find this ingredient in the vast majority of skincare (for good reason). It works to neutralize free radicals, or unstable molecules generated by UV exposure, pollution, and other environmental stressors, before they can cause oxidative damage to your skin cells.
Topically applied tocopherol has been shown to protect against UV damage by ramping up the skin's own natural defense enzymes.
It also acts as a skin conditioning agent; some studies show that regular topical use can improve the skin's water-binding capacity over 2-4 weeks.
This ingredient is especially loved for being a team player. When combined with Vitamin C, the photoprotective effect of both ingredients roughly doubles and the combo also helps reduce UV-induced DNA damage.
This ingredient has some brightening potential but it's more of a prevention ingredient than spot-fader. Cell studies show it can slow down melanin production but it's worth noting that it's not the most powerful brightener out there.
In formulations, it also serves as a stabilizer that helps protect other oxidation-prone ingredients from degrading.
Concentrations usually range from 0.1-1% in most leave-on products.
Trehalose is a disaccharide made of two glucose molecules (glucose is sugar!). Trehalose is used to help moisturize skin. It also has antioxidant properties.
As a humectant, trehalose helps draw moisture from the air to your skin. This helps keep your skin hydrated.
Due to its antioxidant properties, trehalose may help with signs of aging. Antioxidants help fight free-radical molecules, unstable molecules that may damage your skin.
In medicine, trehalose and hyaluronic acid are used to help treat dry eyes.
Some animals, plants, and bacteria create trehalose as a source of energy to survive freeze or lack of water.
Water. It's the most common cosmetic ingredient of all. You'll usually see it at the top of ingredient lists, meaning that it makes up the largest part of the product.
So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.
You'll also recognize water as that liquid we all need to stay alive. If you see this, drink a glass of water. Remember to stay hydrated!
Xanthan gum is used as a stabilizer and thickener within cosmetic products. It helps give products a sticky, thick feeling - preventing them from being too runny.
On the technical side of things, xanthan gum is a polysaccharide - a combination consisting of multiple sugar molecules bonded together.
Xanthan gum is a pretty common and great ingredient. It is a natural, non-toxic, non-irritating ingredient that is also commonly used in food products.