Skin science article
The INKEY List Ceramide Serum Versus DR's Secret Moisturizer 6
The INKEY List Ceramide Serum Versus DR's Secret Moisturizer 6 This barrier-repair treatment is formulated around Sodium Hyaluronate and Ceramide NP to strengthen the skin barrier and hydrate skin. This hydrating treatment is formulated around Aloe Barbadensis
The INKEY List Ceramide Serum Versus DR's Secret Moisturizer 6
This barrier-repair treatment is formulated around Sodium Hyaluronate and Ceramide NP to strengthen the skin barrier and hydrate skin.
This hydrating treatment is formulated around Aloe Barbadensis Leaf Juice to hydrate skin.
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Butylene Glycol
Glycerin
Sodium Hyaluronate
Simmondsia Chinensis Seed Oil
Carbomer
Phenoxyethanol
Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer
Benzyl Alcohol
Squalane
Sodium Lauroyl Lactylate
Sodium PCA
Sodium Hydroxide
Sodium Stearoyl Glutamate
Sodium Lactate
Arginine
Aspartic Acid
Ethylhexylglycerin
Sodium Gluconate
PCA
Polysorbate 60
Dehydroacetic Acid
Ceramide NP
Glycine
Alanine
Sorbitan Isostearate
Ceramide AP
Phytosphingosine
Serine
Cholesterol
Valine
Xanthan Gum
Isoleucine
Proline
Threonine
Histidine
Phenylalanine
Ceramide EOP
Water, Butylene Glycol, Glycerin, Sodium Hyaluronate, Simmondsia Chinensis Seed Oil, Carbomer, Phenoxyethanol, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Benzyl Alcohol, Squalane, Sodium Lauroyl Lactylate, Sodium PCA, Sodium Hydroxide, Sodium Stearoyl Glutamate, Sodium Lactate, Arginine, Aspartic Acid, Ethylhexylglycerin, Sodium Gluconate, PCA, Polysorbate 60, Dehydroacetic Acid, Ceramide NP, Glycine, Alanine, Sorbitan Isostearate, Ceramide AP, Phytosphingosine, Serine, Cholesterol, Valine, Xanthan Gum, Isoleucine, Proline, Threonine, Histidine, Phenylalanine, Ceramide EOP
Aloe Barbadensis Leaf Juice
Glyceryl Stearate
Cetyl Alcohol
Stearic Acid
Phenyl Trimethicone
Ethylhexyl Palmitate
Sodium Lauryl Sulfate
Sorbitol
Tetrasodium EDTA
Parfum
Chlorphenesin
Potassium Sorbate
Water, Glycerin, Aloe Barbadensis Leaf Juice, Glyceryl Stearate, Cetyl Alcohol, Stearic Acid, Phenyl Trimethicone, Ethylhexyl Palmitate, Benzyl Alcohol, Sodium Lactate, Sodium Lauryl Sulfate, Sodium PCA, Sodium Hydroxide, Sorbitol, Tetrasodium EDTA, Proline, Sodium Hyaluronate, Parfum, Chlorphenesin, Potassium Sorbate, Dehydroacetic Acid
Alternatives
Ingredients Explained
These ingredients are found in both products.
Ingredients higher up in an ingredient list are typically present in a larger amount.
Benzyl Alcohol is an aromatic alcohol with several roles: it's a preservative, solvent, and mild fragrance component with a floral scent.
This ingredient has been deemed safe for use in cosmetic formulations at concentrations up to 5%, and up to 10% in hair dyes. You'll typically see 0.5-2% in most rinse-off or leave-on products.
As a preservative, it works by disrupting the membrane of microbial proteins. This helps keep bacteria and fungi from growing in your products.
The sensitization picture is actually quite assuring as well:of nearly 71,000 patients patch tested with benzyl alcohol, only 0.21% showed a positive reaction with most of them being weakly positive.
This led researchers to conclude that benzyl alcohol cannot be regarded as a significant contact allergen.
It is worth noting this ingredient is classified as one of the EU's regulated fragrance allergens and restricted to 1% in finished products.
Labels must also declare it in concentrations above 0.001% in leave-on products and 0.01% in rinse-off products.
At concentrations around 5%, localized redness and itching can appear as a direct irritant response and not as a true allergic reaction.
Dehydroacetic Acid is a synthetic preservative that keeps your products safe from microbes.
As an organic acid, it penetrates microbial cell walls and disrupts cellular metabolism. This makes it effective against bacteria, yeast, and mold.
It is effective at low concentrations (<0.6%). Clinical studies have found it to be non-irritating, non-sensitizing, and non-photosensitizing.
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.
Proline is a non-essential amino acid, meaning your body can make it on its own. In skincare, it is a skin conditioning ingredient that keeps skin soft and hydrated.
It makes up about 23% of the collagen molecule (collagen is the protein responsible for keeping your skin firm) and is involved in your skin's natural hyaluronic acid production. When applied topically, proline can penetrate the skin fairly well due to its small molecular size.
Reviews of this ingredient have found it to be neither a dermal irritant nor a sensitizer.
Fun fact: Proline can be found in protein-rich foods like meat, fish, eggs, and dairy.
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 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.
Sodium Lactate is the sodium salt of lactic acid, an AHA. It is a humectant and sometimes used to adjust the pH of a product.
This ingredient is part of our skin's NMF, or natural moisturizing factor. Our NMF is essential for the hydration of our top skin layers and plasticity of skin. NMF also influences our skin's natural acid mantle and pH, which protects our skin from harmful bacteria.
High percentages of Sodium Lactate can have an exfoliating effect.
Fun fact: Sodium Lactate is produced from fermented sugar.
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%.
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!