Skin science article
Paula's Choice C15 Super Booster Versus Youth To The People 15% Vitamin C + Clean Caffeine Energy Serum
Paula's Choice C15 Super Booster Versus Youth To The People 15% Vitamin C + Clean Caffeine Energy 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 s
Paula's Choice C15 Super Booster Versus Youth To The People 15% Vitamin C + Clean Caffeine Energy 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 3-O-Ethyl Ascorbic Acid and Tetrahexyldecyl Ascorbate to brighten dull-looking skin and fade the look of dark spots.
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
3-O-Ethyl Ascorbic Acid
Tetrahexyldecyl Ascorbate
Pentylene Glycol
Sodium Citrate
Squalane
Triethyl Citrate
Gluconolactone
Citric Acid
Polyhydroxystearic Acid
Polyglyceryl-6 Polyricinoleate
Xanthan Gum
Sodium Hyaluronate
Caffeine
Magnesium Ascorbyl Phosphate
Sodium Stearoyl Glutamate
Sodium Benzoate
Lauroyl Lysine
Passiflora Edulis Fruit Extract
Sclerotium Gum
Lecithin
Ilex Guayusa Leaf Extract
Ilex Paraguariensis Leaf Extract
Pullulan
Mannitol
Hylocereus Undatus Fruit Extract
Zingiber Officinale Root Oil
Calcium Gluconate
Silica
Potassium Sorbate
Ergothioneine
Water, 3-O-Ethyl Ascorbic Acid, Tetrahexyldecyl Ascorbate, Propanediol, Glycerin, Pentylene Glycol, Sodium Citrate, Squalane, Triethyl Citrate, Gluconolactone, Citric Acid, Polyhydroxystearic Acid, Polyglyceryl-6 Polyricinoleate, Xanthan Gum, Sodium Hyaluronate, Caffeine, Magnesium Ascorbyl Phosphate, Sodium Stearoyl Glutamate, Sodium Benzoate, Lauroyl Lysine, Passiflora Edulis Fruit Extract, Sclerotium Gum, Lecithin, Ilex Guayusa Leaf Extract, Ilex Paraguariensis Leaf Extract, Pullulan, Mannitol, Hylocereus Undatus Fruit Extract, Zingiber Officinale Root Oil, Calcium Gluconate, Silica, Potassium Sorbate, Phenoxyethanol, Ergothioneine
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.
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.
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!