Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

Lumene Herkkä Nordic Sensitive Weightless Serum Versus The INKEY List Ectoin Hydro-Barrier Serum

Lumene Herkkä Nordic Sensitive Weightless Serum Versus The INKEY List Ectoin Hydro-Barrier Serum This barrier-repair serum is formulated around Ceramide NP to strengthen the skin barrier and calm redness. This barrier-repair serum is formulated around Ectoin a

Lumene Herkkä Nordic Sensitive Weightless Serum Versus The INKEY List Ectoin Hydro-Barrier Serum

This barrier-repair serum is formulated around Ceramide NP to strengthen the skin barrier and calm redness.

This barrier-repair serum is formulated around Ectoin and Panthenol to strengthen the skin barrier and hydrate skin.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Vaccinium Myrtillus Fruit Juice

Water

Propanediol

Butylene Glycol

Xylitol

Glycerin

Pentylene Glycol

Betaine

Inulin

Avena Sativa Bran Extract

Ceramide NP

Ceramide AP

Phytosphingosine

Cholesterol

Ceramide EOP

Phenoxyethanol

Saccharide Isomerate

Ethylhexylglycerin

Xanthan Gum

Hydroxyacetophenone

Squalane

Chondrus Crispus

Sodium Gluconate

Polyglyceryl-10 Stearate

Sodium Hyaluronate

Triethyl Citrate

Biosaccharide Gum-1

Polyglyceryl-6 Behenate

Behenic Acid

Cetearyl Alcohol

Citric Acid

Glyceryl Stearate

Sodium Citrate

Sodium Levulinate

Sodium Carrageenan

Potassium Sorbate

Sodium Cetearyl Sulfate

Maris Sal

Vaccinium Myrtillus Fruit Juice, Water, Propanediol, Butylene Glycol, Xylitol, Glycerin, Pentylene Glycol, Betaine, Inulin, Avena Sativa Bran Extract, Ceramide NP, Ceramide AP, Phytosphingosine, Cholesterol, Ceramide EOP, Phenoxyethanol, Saccharide Isomerate, Ethylhexylglycerin, Xanthan Gum, Hydroxyacetophenone, Squalane, Chondrus Crispus, Sodium Gluconate, Polyglyceryl-10 Stearate, Sodium Hyaluronate, Triethyl Citrate, Biosaccharide Gum-1, Polyglyceryl-6 Behenate, Behenic Acid, Cetearyl Alcohol, Citric Acid, Glyceryl Stearate, Sodium Citrate, Sodium Levulinate, Sodium Carrageenan, Potassium Sorbate, Sodium Cetearyl Sulfate, Maris Sal

Caprylic/Capric Triglyceride

Coconut Alkanes

Ectoin 2%

Hydrolyzed Sodium Hyaluronate

Maltodextrin

Sodium Stearoyl Glutamate

Panthenol

Sclerotium Gum

Jojoba Esters

Coco-Caprylate/Caprate

Helianthus Annuus Seed Wax

Avena Sativa Kernel Extract

Leuconostoc/Radish Root Ferment Filtrate

Sodium Hyaluronate Crosspolymer

Hyaluronic Acid

Polyglycerin-3

Water, Propanediol, Caprylic/Capric Triglyceride, Coconut Alkanes, Ectoin 2%, Hydrolyzed Sodium Hyaluronate, Sodium Hyaluronate, Maltodextrin, Phenoxyethanol, Sodium Stearoyl Glutamate, Panthenol, Cetearyl Alcohol, Sclerotium Gum, Xanthan Gum, Glyceryl Stearate, Jojoba Esters, Coco-Caprylate/Caprate, Ethylhexylglycerin, Sodium Citrate, Helianthus Annuus Seed Wax, Citric Acid, Polyglyceryl-10 Stearate, Avena Sativa Kernel Extract, Glycerin, Leuconostoc/Radish Root Ferment Filtrate, Triethyl Citrate, Pentylene Glycol, Polyglyceryl-6 Behenate, Sodium Hyaluronate Crosspolymer, Ceramide NP, Hyaluronic Acid, Ceramide AP, Cholesterol, Phytosphingosine, Behenic Acid, Sodium Levulinate, Polyglycerin-3, Potassium Sorbate, Sodium Cetearyl Sulfate, 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.

Behenic acid is a long-chain fatty acid with 22 carbon atoms (C22) that is naturally found in moringa, rapeseed, and peanut oil.

In skincare, it's about as drama-free as ingredients come. It acts primarily as a texture enhancer, thickener, and opacifying agent that gives richness and viscosity to formulas.

On skin, it forms a protective, emollient layer that helps with moisture retention and contributes to barrier integrity.

In vitro studies on genotoxicity have come back negative and this ingredient is well-tolerated. Typical use concentrations range from 0.024%-22%.

This ingredient may not be fungal acne safe because Behenic acid falls within the C11-24 fatty acid range capable of supporting Malassezia growth.

Ceramide AP is is a skin-identical lipid that mimics what your skin already makes naturally. Ceramides help maintain epidermal integrity and barrier function.

You'll often see this ingredient paired with other ceramides (like ceramide NP), cholesterol, or fatty acids because this combination best mimics the natural lipid mix your skin already has.

The skin's ability to produce ceramides gets disrupted in skin conditions like eczema. This in turn weakens the skin barrier and applying ceramides topically has been shown to replenish what's been lost to restore barrier function.

Most of the studies with Ceramide AP test it as part of a multi-ceramide complex; studies reinforce ceramide AP's role in rebalancing ceramides in skin and improving skin hydration.

Ceramide EOP is formally known as Ceramide 1.

It is naturally found in skin and part of the intercellular "mortar" holding everything together in your outermost layer.

EOP stands for a linked Ester fatty acid, a linked Omega hydroxy fatty acid, and the Phytosphingosine base.

What makes Ceramide EOP special is its ultra-long fatty acid chain; this unique structure allows it to bridge the lipid layers in your skin barrier to prevent water loss (something no other ceramide can do).

Low levels of Ceramide EOP have been found in people with eczema and psoriasis.

Using it together with other ceramides, cholesterol, and linoleic acid have been shown to meaningfully improve hydration and reduce water loss.

In one clinical study, a regimen using Ceramide EOP, NP, and AP led to significant symptom improvements in patients with eczema, psoriasis, and dry skin in just 4 weeks.

You'll usually see concentrations between 0.1-0.5% in formulations. Overall, this is a well-tolerated and safe ingredient for cosmetic use.

Ceramide NP (formerly known as Ceramide 3) is one of the skin's naturally occurring lipids.

Since ceramides are the major lipid components of the skin, they are crucial for maintaining skin barrier and hydration. Ceramide NP most closely mirrors the dominant kind in human skin amongst ceramide subtypes.

This ceramide works by slotting into gaps within the stratum corneum's lipid matrix to limit trans-epidermal water loss (TEWL) and shield the skin against external irritants.

A study with 312 patients found that using a ceramide-containing routine for 4 weeks reduced the severity of atopic dermatitis by over 61%.

Another clinical study in subjects aged 60 and older found that a ceramide body wash and moisturizer improved skin dryness and itchy skin in 15 days.

Overall, ceramides are considered non-irritating and safety tests have found little to no observable adverse effects from using this ingredient.

Ceramide NP is usually sourced from plants (like soybean or rice bran), or produced synthetically.

Cetearyl alcohol is a waxy mixture of two fatty alcohols: cetyl alcohol and stearyl alcohol. It is an emollient and emulsifier.

Despite having "alcohol" in its name, it has nothing to do with drying solvent alcohols; the FDA also allows "alcohol-free" products to contain fatty alcohols like this ingredient.

It plays several roles in a formula:

Typical use levels for this ingredient sit around 1-10% and the Cosmetic Ingredient Review Expert Panel has affirmed safety at concentrations up to 25% in leave-on products.

Multiple assessments have found it to be non-irritating and non-sensitizing to most people.

However, there have been some cases of allergic contact dermatitis in patients with chronically compromised skin barriers.

Cetearyl alcohol has a comedogenic rating of 2 and irritancy rating of 1. Both of these numbers come from the 1989 study that used rabbit ears; a "2" means mildly comedogenic and a "1" means low irritancy.

Here's the catch: rabbit skin is more sensitive than human skin and throws a lot of false positives. A 1996 reappraisal found that ingredients rated 1-2 in the rabbit ear tests are generally safe for humans.

Remember comedogenic ratings are unable to assess the entire formula of a product or how it will react on your skin. Just be sure to patch test if you are unsure about certain ingredients.

This ingredient is not fungal acne safe. Cetearyl alcohol is a fatty alcohol with chain lengths that fall within the range that Malassezia can metabolize.

A 2019 study has also observed Malassezia growth in the presence of this ingredient, confirming it to be not-fungal acne safe.

Cholesterol is a lipid that is naturally found in human skin and is one of the three key components of your skin barrier. In skincare, it is an emollient and barrier-repairing ingredient.

It works by fitting directly into the lipid layers of skin to help restore structure and reduce transepidermal water loss (TEWL).

This is a great ingredient for dry, compromised, or aging skin; our skin starts to produce less cholesterol with age.

Research shows cholesterol works best in combination with ceramides and fatty acids, the other two major components in your skin barrier.

Cholesterol is also a well-establish penetration enhancer and can help other actives absorb more effectively.

Cosmetic-grade cholesterol is usually derived from lanolin but plant and synthetic options also exist. We recommend reaching out to the brand if you have questions about their source of cholesterol.

Citric Acid is an alpha hydroxy acid (AHA) naturally found in citrus fruits like oranges, lemons, and limes.

Like other AHAs, citric acid can exfoliate skin by breaking down the bonds that hold dead skin cells together. This helps reveal smoother and brighter skin underneath.

However, this exfoliating effect only happens at high concentrations (20%) which can be hard to find in cosmetic products.

Due to this, citric acid is usually included in small amounts as a pH adjuster. This helps keep products slightly more acidic and compatible with skin's natural pH.

In skincare formulas, citric acid can:

While it can provide some skin benefits, research shows lactic acid and glycolic acid are generally more effective and less irritating exfoliants.

Most citric acid used in skincare today is made by fermenting sugars (usually from molasses). This synthetic version is identical to the natural citrus form but easier to stabilize and use in formulations.

Rosacea skin has a lower threshold for acids generally, with 62.5% of rosacea subjects in one study reacting to lactic acid in a sting test. This is why we mark citric acid as a potential rosacea trigger.

However, this ingredient shows up as a pH adjuster or chelator at roughly 0.1-1% in many products. These low levels are unlikely to be an issue for rosacea skin and becomes a potential trigger at exfoliating concentrations (20%). Because everybody's skin is unique, we recommend a patch test if you are unsure.

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.

Glyceryl Stearate is made by reacting glycerin with stearic acid (typically sourced from plant oils like palm or coconut). It's an emulsifier, emollient, and mild occlusive.

Emulsifiers help ingredients like oil and water stay mixed so your formula stays nicely blended and uniform in texture.

This ingredient is typically used in concentrations between 1-10%. Studies have found it to be non-sensitizing, non-phototoxic, and non-photoallergenic.

A close cousin of this ingredient is Glyceryl Stearate SE ("self-emulsifying"). This just has a small amount of sodium or potassium stearate added so it can emulsify without a co-emulsifier.

Since this ingredient is an ester of a C18 fatty acid, it may not be fungal acne safe. The Malassezia yeast can potentially metabolize within the C11-C24 range.

Fun fact: The human body also creates Glyceryl Stearate naturally.

Pentylene Glycol (1,2-pentanediol) is a multitasking little diol with three main roles in a formula:

Research on alkanediols (the family pentylene glycol belongs to) show they work by disrupting microbial cell membranes. This disruption helps the primary preservative system in a product work more effectively at lower doses.

On the safety side, the Cosmetic Ingredient Review Expert Panel has concluded this ingredient to be safe as used in current cosmetic practices + concentrations.

Typical use levels in a formula run about 1-5%.

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.

Phytosphingosine is a phospholipid naturally found in our skin as a building block for ceramides.. It helps moisturize, soothe, and protect skin.

Phytosphingosine contributes to your skin's natural moisturizing factor (NMF). The NMF is responsible for hydration, a strong barrier, and plasticity. Our NMF decreases with age. Increasing NMF leads to more healthy and hydrated skin.

Studies show products formulated with NMF ingredients help strengthen our skin's barrier. Having a healthy skin barrier reduces irritation and increases hydration. Our skin barrier is responsible for having plump and firm skin. It also helps protect our skin against infection, allergies, and inflammation.

Fun fact: Phytosphingosine is abundant in plants and fungi.

More ingredients that help boost collagen in skin:

Polyglyceryl-10 Stearate is a skin conditioner that is basically a fatty acid (stearic acid) hooked up to a chain of glycerin units.

It is a skin conditioning agent that helps skin feel soft, smooth, and hydrated.

Beyond that, it also helps emulsify and cleanse: it helps oil and water phases stay blended in moisturizers, serums, and cleansers.

This ingredient has been found to be safe in cosmetics at present concentrations and practices of use.

Research on Malassezia shows the yeast can metabolize stearic acid as a growth substrate; this ingredient is not fungal acne safe.

Polyglyceryl-6 Behenate isn't fungal acne safe.

Potassium Sorbate is a preservative used to prevent yeast and mold in products. It is commonly found in both cosmetic and food products.

This ingredient comes from potassium salt derived from sorbic acid. Sorbic acid is a natural antibiotic and effective against fungus.

Both potassium sorbate and sorbic acid can be found in baked goods, cheeses, dried meats, dried fruit, ice cream, pickles, wine, yogurt, and more.

You'll often find this ingredient used with other preservatives.

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 Cetearyl Sulfate is a type of sulfate.

Sodium Citrate is the sodium salts of citric acid. In skincare, it is used to alter pH levels and acts as a preservative.

Its main functions are to maintain the pH of a product and neutralize metal ions.

The acidity of our skin is maintained by our glands and skin biome; normal pH level of skin is slightly acidic (~4.75-5.5).

Being slightly acidic allows our skin to create an "acid mantle". This acid mantle is a thin barrier that protects our skin from bacteria and contaminants.

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 levulinate is the a sodium salt of Levulinic Acid. Oncedissolved in an aqueous solution, the two ingredients become identical. It is usually derived from renewable plant sources like corn starch or sugarcane.

In skincare, it mostly acts as a skin conditioning agent that keeps skin soft and hydrated. It also acts as a preservative booster by inhibiting the growth of mold, yeast, and bacteria.

It's often paired with Sodium Anisate as the two create a broad-spectrum preservative system that is popular in "natural" formulations.

This ingredient is water-soluble.

The CIR Expert Panel for Cosmetic Ingredient Safety has concluded this ingredient to be non-irritated and there are no restrictions for use in EU cosmetics. The FDA also allows this ingredient to be used as a food-grade flavoring agent.

Triethyl Citrate comes from citric acid. It has masking, perfuming, and solvent properties. As a solvent, this ingredient helps disperse ingredients evenly in skincare.

One manufacturer claims this ingredient can:

According to perfume manufacturers, this ingredient is almost odorless but has a mild fruity, wine and plum scent. It can be used to mask the scent of other ingredients.

This ingredient can be plant-sourced or synthetic; it can naturally be found in cabbage and white wine.

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!

Xanthan gum is used as a stabilizer and thickener within cosmetic products. It helps give products a sticky, thick feeling - preventing them from being too runny.

On the technical side of things, xanthan gum is a polysaccharide - a combination consisting of multiple sugar molecules bonded together.

Xanthan gum is a pretty common and great ingredient. It is a natural, non-toxic, non-irritating ingredient that is also commonly used in food products.

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. 01Citrus Aurantium Dulcis Fruit Water
  2. 02Water
  3. 03Aloe Barbadensis Leaf Juice
  4. 04Niacinamide
  5. 05Erythritol
  6. 06Citric Acid
  7. 07Tranexamic Acid
  8. 08Propanediol
  9. 09Kojic Acid
  10. 10Sodium Hyaluronate
  11. 11Glycyrrhiza Glabra Root Extract
  12. 12Glycerin
  13. 13Caesalpinia Spinosa Gum
  14. 14Xanthan Gum
  15. 15Sodium Phytate
  16. 16Sodium Benzoate
  17. 17Potassium Sorbate
  18. 18Hydroxyacetophenone
  19. 19Citrus Aurantium Dulcis Fruit Water, Water, Aloe Barbadensis Leaf Juice, Niacinamide, Erythritol, Citric Acid, Tranexamic Acid, Propanediol, Kojic Acid, Sodium Hyaluronate, Glycyrrhiza Glabra Root Extract, Glycerin, Caesalpinia Spinosa Gum, Xanthan …
  20. 20Butylene Glycol
Source · skinsort.com
02

Product index

Related product references

Product

The Inkey List Caffeine Eye Cream

The Inkey List Caffeine Eye Cream The Inkey List Caffeine Eye Cream ingredients explained: Aqua (Water), Glycerin, Dicaprylyl Carbonate, Propanediol, Polyglyceryl-6 Distearate, Cetyl Alcoho…

Source: incidecoder.comView reference →
03

Comparison edit

Read side by side