Skin science article
La Roche-Posay Pure Vitamin C Eye Cream Versus Kiehl's Powerful-Strength Dark Circle Reducing Vitamin C Eye Serum
La Roche-Posay Pure Vitamin C Eye Cream Versus Kiehl's Powerful-Strength Dark Circle Reducing Vitamin C Eye Serum This anti-aging eye moisturizer is formulated around Ascorbic Acid and Madecassoside to soften the look of wrinkles and brighten dull-looking skin
La Roche-Posay Pure Vitamin C Eye Cream Versus Kiehl's Powerful-Strength Dark Circle Reducing Vitamin C Eye Serum
This anti-aging eye moisturizer is formulated around Ascorbic Acid and Madecassoside to soften the look of wrinkles and brighten dull-looking skin.
This brightening eye moisturizer is formulated around Ascorbic Acid and Adenosine to fade the look of dark spots and soften the look of wrinkles.
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Glycerin
Dimethicone
Butyrospermum Parkii Butter
Limnanthes Alba Seed Oil
Ascorbic Acid
Mannose
Butylene Glycol
Paraffinum Liquidum
Ammonium Polyacryloyldimethyl Taurate
Cetyl Alcohol
PEG-100 Stearate
Glyceryl Stearate
Polymethylsilsesquioxane
Potassium Hydroxide
Paraffin
Sodium Styrene/Ma Copolymer
Microcrystalline Wax
Madecassoside
Dimethicone/Vinyl Dimethicone Crosspolymer
Dimethiconol
Disodium EDTA
Hydrolyzed Hyaluronic Acid
Caprylyl Glycol
Acetyl Dipeptide-1 Cetyl Ester
Xanthan Gum
Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate
Phenoxyethanol
Water, Glycerin, Dimethicone, Butyrospermum Parkii Butter, Limnanthes Alba Seed Oil, Ascorbic Acid, Mannose, Butylene Glycol, Paraffinum Liquidum, Ammonium Polyacryloyldimethyl Taurate, Cetyl Alcohol, PEG-100 Stearate, Glyceryl Stearate, Polymethylsilsesquioxane, Potassium Hydroxide, Paraffin, Sodium Styrene/Ma Copolymer, Microcrystalline Wax, Madecassoside, Dimethicone/Vinyl Dimethicone Crosspolymer, Dimethiconol, Disodium EDTA, Hydrolyzed Hyaluronic Acid, Caprylyl Glycol, Acetyl Dipeptide-1 Cetyl Ester, Xanthan Gum, Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate, Phenoxyethanol
Propylene Glycol
Dimethicone Crosspolymer
Cetyl PEG/PPG-10/1 Dimethicone
Cyclohexasiloxane
Hydroxyethylpiperazine Ethane Sulfonic Acid
Lauroyl Lysine
Aluminum Starch Octenylsuccinate
Polysilicone-11
CI 77891
Adenosine
Steareth-20
Chlorhexidine Digluconate
N-Hydroxysuccinimide
Sodium Citrate
Potassium Sorbate
Palmitoyl Tripeptide-1
Chrysin
Palmitoyl Tetrapeptide-7
Citric Acid
Biotin
Propylene Glycol, Dimethicone, Glycerin, Ascorbic Acid, Dimethicone Crosspolymer, Cetyl PEG/PPG-10/1 Dimethicone, Cyclohexasiloxane, Water, Hydroxyethylpiperazine Ethane Sulfonic Acid, Lauroyl Lysine, Aluminum Starch Octenylsuccinate, Polysilicone-11, CI 77891, Adenosine, Hydrolyzed Hyaluronic Acid, Steareth-20, Chlorhexidine Digluconate, N-Hydroxysuccinimide, Sodium Citrate, Potassium Sorbate, Palmitoyl Tripeptide-1, Chrysin, Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate, Palmitoyl Tetrapeptide-7, Citric Acid, Biotin
Alternatives
Ingredients Explained
These ingredients are found in both products.
Ingredients higher up in an ingredient list are typically present in a larger amount.
Ascorbic Acid is is pure Vitamin C and is the biologically active form used directly by skin.
Not only is vitamin C great for your overall health and immune system, but it also has plenty of benefits for your skin. It is best supported by academic literature for:
Topical vitamin C has been shown to help neutralize oxidative stress from UV and pollution, helping to improve photoaging and hyperpigmentation when used consistently.
One clinical study found that using 5% topical vitamin C for six months improved signs of photodamaged skin, both on the surface and in the deeper structural layers of the skin.
While vitamin C doesn’t replace sunscreen, studies show it can boost photoprotection when combined with Vitamin E and ferulic acid. These two ingredients help improve stability and protective effects.
The big downside of this ingredient is formulation difficulty. Vitamin C is prone to oxidation and doesn't penetrate the skin unless formulated correctly. Research found that vitamin C absorbs into the skin best at a low pH (< 3.5) with about 20% being the upper limit for effective absorption.
Skin levels can saturate after repeated application; this means your skin won’t keep absorbing more once it’s full of vitamin C. This is why more isn’t always better with vitamin C and why very high concentrations don’t necessarily give extra benefits.
Ascorbic acid generally works well with many skincare ingredients but can be irritating when combined with other active ingredients. Strong oxidizing acne treatments like benzoyl peroxide can reduce the effectiveness of vitamin C if they are used at the same time; they are often recommended for use at different times of day.
Read more about other types of Vitamin C:
Foods rich with vitamin C include oranges, strawberries, broccoli, bell peppers, and more. When consuming Vitamin C, your skin receives a portion of the nutrients.
Dimethicone is a type of synthetic silicone created from natural materials such as quartz. It is also known as polydimethylsiloxane.
What it does:
Dimethicone comes in different viscosities:
Depending on the viscosity, dimethicone has different properties.
Ingredients lists don't always show which type is used, so we recommend reaching out to the brand if you have questions about the viscosity.
This ingredient is unlikely to cause irritation because it does not get absorbed into skin. However, people with silicone allergies should be careful about using this ingredient.
Note: Dimethicone may contribute to pilling. This is because it is not oil or water soluble, so pilling may occur when layered with products. When mixed with heavy oils in a formula, the outcome is also quite greasy.
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.
Hydrolyzed Hyaluronic Acid is hyaluronic acid (HA) that is broken down into lower molecular weight fragments.
It's a humectant that pulls and holds water in the skin to help with hydration, plumpness, and reduce transepidermal water loss.
Because hydrolyzed hyaluronic acid is smaller in size, it can slip past your outermost layer of skin more easily than full-sized HA.
Most formulations will combine all sizes to get the best of both worlds.
Typical usage levels range from 0.01-1%. Any percentage higher than 2% might become goopy and tacky.
Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate (long name, huh?) is a synthetic antioxidant.
It is used to help stabilize other antioxidants or prevent the color from changing in a product.
As an antioxidant, it helps fight free-radical molecules. Free-radical molecules are capable of damaging our cells and other genetic material. Thus, antioxidants may reduce the signs of aging.
This ingredient is oil-soluble.
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!