Skin science article
Paula's Choice C15 Super Booster Versus Dermalogica Biolumin C Serum
Paula's Choice C15 Super Booster Versus Dermalogica Biolumin C Serum This brightening serum is formulated around Ascorbic Acid and Ferulic Acid to brighten dull-looking skin and soften the look of wrinkles. This brightening serum is formulated around Lactic Ac
Paula's Choice C15 Super Booster Versus Dermalogica Biolumin C Serum
This brightening serum is formulated around Ascorbic Acid and Ferulic Acid to brighten dull-looking skin and soften the look of wrinkles.
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
Ascorbic Acid
Dipropylene Glycol
Propanediol
Glycerin
Ethoxydiglycol
Sodium Hydroxide
PPG-26-Buteth-26
PEG-40 Hydrogenated Castor Oil
Bisabolol
Ferulic Acid
Sodium Phytate
Decylene Glycol
Tocopherol
1,2-Hexanediol
Sphingomonas Ferment Extract
Phenoxyethanol
Water, Ascorbic Acid, Dipropylene Glycol, Propanediol, Glycerin, Ethoxydiglycol, Sodium Hydroxide, PPG-26-Buteth-26, PEG-40 Hydrogenated Castor Oil, Bisabolol, Ferulic Acid, Sodium Phytate, Decylene Glycol, Tocopherol, 1,2-Hexanediol, Sphingomonas Ferment Extract, Phenoxyethanol
Butylene Glycol
Lactic Acid
Salvia Hispanica Seed Extract
Sodium PCA
Palmitoyl Tripeptide-5
Sophora Japonica Flower Extract
Ascorbyl Methylsilanol Pectinate
Sodium Hyaluronate
Dipotassium Glycyrrhizate
Aminopropyl Ascorbyl Phosphate
Trehalose
Polyacrylate-13
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
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.
Ethoxydiglycol (aka Diethylene Glycol Monoethyl Ether) is one of the cosmetic world's quiet problem solvers.
In a formula, it is a solvent that dissolves tricky ingredients that don't want to mix in and helps spread ingredients evenly across your skin without leaving a greasy or sticky feeling
This makes it great for hard-to-dissolve actives like vitamin C, benzoyl peroxide, and self-tanner DHA.
It also has mild humectant and penetration enhancer abilities so it can help some actives absorb a little deeper.
The penetration boost is backed by lab research: studies using human skin samples found it improved how well an active dissolves into the upper layer of skin rather than tearing down your skin barrier. Reviews of its mechanism also describe it interacting gently with the lipids and water in your outermost layer of skin.
Just know this penetration-enhancing effect is not universal. It helps a lot in some formulas and did very little in others (so the benefit really depends on the specific product).
Safety-wise, the evidence is reassuring. The Cosmetic Ingredient Review Expert Panel reviewed it and concluded it's safe for use in cosmetics and recognized it as non-irritating, non-sensitizing, and non-comedogenic in skincare.
Typical leave-on skincare usage lands around 1-10%. The EU has sets caps of 2.6% in non-spray products, 10% in rinse-offs, 7% in oxidative hair dye, and 5% in non-oxidative hair dye.
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 Hydroxide is also known as lye or caustic soda. It is used to adjust the pH of products; many ingredients require a specific pH to be effective.
In small amounts, sodium hydroxide is considered safe to use. However, large amounts may cause chemical burns due to its high alkaline.
Your skin has a natural pH and acid mantle. This acid mantle helps prevent harmful bacteria from breaking through. The acid mantle also helps keep your skin hydrated.
"Alkaline" refers to a high pH level. A low pH level would be considered acidic.
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.
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!