Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

The INKEY List Peptide Moisturizer Versus The INKEY List Ceramide Serum

The INKEY List Peptide Moisturizer Versus The INKEY List Ceramide Serum This barrier-repair treatment is formulated around Sodium Hyaluronate and Ceramide NP to strengthen the skin barrier and hydrate skin. What's inside Key Ingredients Benefits Concerns Ingre

The INKEY List Peptide Moisturizer Versus The INKEY List Ceramide Serum

This barrier-repair treatment is formulated around Sodium Hyaluronate and Ceramide NP to strengthen the skin barrier and hydrate skin.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Caprylic/Capric Triglyceride

Glycerin

C12-15 Alkyl Benzoate

Cetearyl Alcohol

Glyceryl Stearate Se

Betaine

Butylene Glycol

Phenoxyethanol

Benzyl Alcohol

Carbomer

Butyrospermum Parkii Butter

Sodium Stearoyl Glutamate

Sodium Hydroxide

Ethylhexylglycerin

Sodium Gluconate

Tocopheryl Acetate

Dehydroacetic Acid

Hydrogenated Lecithin

Phenethyl Alcohol

Acetyl Hexapeptide-37

Maltodextrin

Pentapeptide-48

Water, Caprylic/Capric Triglyceride, Glycerin, C12-15 Alkyl Benzoate, Cetearyl Alcohol, Glyceryl Stearate Se, Betaine, Butylene Glycol, Phenoxyethanol, Benzyl Alcohol, Carbomer, Butyrospermum Parkii Butter, Sodium Stearoyl Glutamate, Sodium Hydroxide, Ethylhexylglycerin, Sodium Gluconate, Tocopheryl Acetate, Dehydroacetic Acid, Hydrogenated Lecithin, Phenethyl Alcohol, Acetyl Hexapeptide-37, Maltodextrin, Pentapeptide-48

Sodium Hyaluronate

Simmondsia Chinensis Seed Oil

Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer

Squalane

Sodium Lauroyl Lactylate

Sodium PCA

Sodium Lactate

Arginine

Aspartic Acid

PCA

Polysorbate 60

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

Reviews

Be the first to review

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.

Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:

Overall, Butylene Glycol is a safe and well-rounded ingredient that works well with other ingredients.

Though this ingredient works well with most skin types, some people with sensitive skin may experience a reaction such as allergic rashes, closed comedones, or itchiness.

Carbomer is a synthetic thickening and gelling agent. It's basically the ingredient that gives a lot of serums, gels, creams, and sunscreens their smooth, non-sticky texture.

Although legally permitted at very high levels, carbomers are normally used at concentrations below 1%.

It also needs to be neutralized to actually thicken, and because it is a large molecule, it doesn't really penetrate the skin barrier.

Allergy-wise, the risk is very low. Clinical studies show carbomers have low potential for skin irritation/sensitization even at concentrations up to 100%.

A 2024 UK study patch-tested 1,302 patients and found true allergy to the parent group of carbomer to be rare with no confirmed relevant reactions.

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.

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.

This is the synthetic salt of gluconic acid, a form of PHA and mild exfoliant.

It is mainly used to stabilize oil and butter formulations from going bad. Sodium gluconate is a humectant, pH regulator, and chelating agent.

Chelating agents help neutralize unwanted metals from affecting the formulation.

Sodium gluconate is water-soluble.

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 Stearoyl Glutamate is an amino-acid based emulsifier. It is made by combining stearic acid with L-glutamic acid and neutralizing it to a sodium salt.

As an emulsifier, it works mainly as an oil-in-water one and helps keep the oil and water in your formulas blended. It also contributes to a smooth, non-greasy skin feel.

This ingredient is biodegradable and commonly available in natural/COSMOS-certified grades.

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!

Similar Comparisons

The reference edit

Ingredients, questions
& further reading.

Connected source records selected through this article’s public topic index.

01

Formula cabinet

Ingredients & structured notes

Ingredient index

Ingredients Side-by-side

  1. 01Water
  2. 02Caprylic/Capric Triglyceride
  3. 03Glycerin
  4. 04C12-15 Alkyl Benzoate
  5. 05Cetearyl Alcohol
  6. 06Glyceryl Stearate Se
  7. 07Betaine
  8. 08Butylene Glycol
  9. 09Phenoxyethanol
  10. 10Benzyl Alcohol
  11. 11Carbomer
  12. 12Butyrospermum Parkii Butter
  13. 13Sodium Stearoyl Glutamate
  14. 14Sodium Hydroxide
  15. 15Ethylhexylglycerin
  16. 16Sodium Gluconate
  17. 17Tocopheryl Acetate
  18. 18Dehydroacetic Acid
  19. 19Hydrogenated Lecithin
  20. 20Phenethyl Alcohol
Source · skinsort.com
03

Comparison edit

Read side by side