Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

The INKEY List Caffeine Eye Cream Versus Olehenriksen Banana Bright+ Eye Crème

The INKEY List Caffeine Eye Cream Versus Olehenriksen Banana Bright+ Eye Crème This anti-aging eye moisturizer is formulated around Caffeine and Palmitoyl Tetrapeptide-7 to soften the look of wrinkles. This brightening eye moisturizer is formulated around 3-O-

The INKEY List Caffeine Eye Cream Versus Olehenriksen Banana Bright+ Eye Crème

This anti-aging eye moisturizer is formulated around Caffeine and Palmitoyl Tetrapeptide-7 to soften the look of wrinkles.

This brightening eye moisturizer is formulated around 3-O-Ethyl Ascorbic Acid and Simmondsia Chinensis Seed Oil to brighten dull-looking skin and hydrate skin.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Glycerin

Dicaprylyl Carbonate

Propanediol

Polyglyceryl-6 Distearate

Cetyl Alcohol

Glyceryl Behenate

Phenoxyethanol

Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer

Jojoba Esters

Albizia Julibrissin Bark Extract

Squalane

Caffeine

Polyglyceryl-3 Beeswax

Phospholipids

Ethylhexylglycerin

Xanthan Gum

Glycine Soja Oil

Polysorbate 60

Sodium Phytate

Glycolipids

Sorbitan Isostearate

Butylene Glycol

Citric Acid

Glycine Soja Sterols

Leuconostoc/Radish Root Ferment Filtrate

Hyaluronic Acid

Sodium Benzoate

Tocopherol

Carbomer

Darutoside

Sodium Lactate

Polysorbate 20

Palmitoyl Tetrapeptide-7

Palmitoyl Tripeptide-1

Water, Glycerin, Dicaprylyl Carbonate, Propanediol, Polyglyceryl-6 Distearate, Cetyl Alcohol, Glyceryl Behenate, Phenoxyethanol, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Jojoba Esters, Albizia Julibrissin Bark Extract, Squalane, Caffeine, Polyglyceryl-3 Beeswax, Phospholipids, Ethylhexylglycerin, Xanthan Gum, Glycine Soja Oil, Polysorbate 60, Sodium Phytate, Glycolipids, Sorbitan Isostearate, Butylene Glycol, Citric Acid, Glycine Soja Sterols, Leuconostoc/Radish Root Ferment Filtrate, Hyaluronic Acid, Sodium Benzoate, Tocopherol, Carbomer, Darutoside, Sodium Lactate, Polysorbate 20, Palmitoyl Tetrapeptide-7, Palmitoyl Tripeptide-1

Simmondsia Chinensis Seed Oil

Butyrospermum Parkii Butter

Isododecane

Coconut Alkanes

3-O-Ethyl Ascorbic Acid

Cetearyl Alcohol

C18-38 Alkyl Hydroxystearoyl Stearate

Dilinoleic Acid/Propanediol Copolymer

Polymethylsilsesquioxane

Cocoyl Proline

Dimethicone Crosspolymer

Pentaerythrityl Tetraisostearate

Tetrahexyldecyl Ascorbate

Ascorbic Acid

Gold

Glutathione

Citrus Nobilis Fruit Extract

Citrus Paradisi Peel Extract

Glucosyl Hesperidin

Tamarindus Indica Seed Polysaccharide

Poncirus Trifoliata Fruit Extract

Morus Alba Root Extract

Linoleic Acid

Linolenic Acid

Caprylyl Glycol

Coco-Caprylate/Caprate

Polyglyceryl-3 Cocoate

Polyglyceryl-4 Caprate

Polyglyceryl-6 Caprylate

Polyglyceryl-6 Ricinoleate

Hdi/Trimethylol Hexyllactone Crosspolymer

Polyacrylate-13

Polyglyceryl-3 Stearate

Sodium Citrate

Polyisobutene

Beheneth-5

Acrylates/C10-30 Alkyl Acrylate Crosspolymer

Behenyl Alcohol

Sodium Hydroxide

Sorbic Acid

Hydrolyzed Vegetable Protein

Stearic Acid

Palmitic Acid

Oleic Acid

Sorbitol

Silica

1,2-Hexanediol

Mica

Titanium Dioxide

CI 77891

CI 77491

Water, Simmondsia Chinensis Seed Oil, Butyrospermum Parkii Butter, Isododecane, Coconut Alkanes, 3-O-Ethyl Ascorbic Acid, Cetearyl Alcohol, Glycerin, C18-38 Alkyl Hydroxystearoyl Stearate, Dilinoleic Acid/Propanediol Copolymer, Polymethylsilsesquioxane, Cocoyl Proline, Dimethicone Crosspolymer, Pentaerythrityl Tetraisostearate, Tetrahexyldecyl Ascorbate, Ascorbic Acid, Gold, Glutathione, Citrus Nobilis Fruit Extract, Citrus Paradisi Peel Extract, Glucosyl Hesperidin, Tocopherol, Tamarindus Indica Seed Polysaccharide, Poncirus Trifoliata Fruit Extract, Morus Alba Root Extract, Linoleic Acid, Linolenic Acid, Jojoba Esters, Caprylyl Glycol, Coco-Caprylate/Caprate, Propanediol, Polyglyceryl-3 Cocoate, Polyglyceryl-4 Caprate, Polyglyceryl-6 Caprylate, Polyglyceryl-6 Ricinoleate, Hdi/Trimethylol Hexyllactone Crosspolymer, Polyacrylate-13, Butylene Glycol, Polyglyceryl-3 Stearate, Polysorbate 20, Sodium Citrate, Polyisobutene, Beheneth-5, Acrylates/C10-30 Alkyl Acrylate Crosspolymer, Behenyl Alcohol, Sodium Hydroxide, Sorbic Acid, Sorbitan Isostearate, Citric Acid, Hydrolyzed Vegetable Protein, Stearic Acid, Palmitic Acid, Oleic Acid, Sorbitol, Silica, Sodium Benzoate, 1,2-Hexanediol, Xanthan Gum, Phenoxyethanol, Leuconostoc/Radish Root Ferment Filtrate, Mica, Titanium Dioxide, CI 77891, CI 77491

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.

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.

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.

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.

Jojoba Esters is a wax created from Jojoba oil. It is an emollient and film-forming ingredient. In bead form, it is an exfoliator.

This ingredient has high oxidative stability, meaning it doesn't break down when exposed to oxygen.

Its similarity to our skin's natural oils makes it a great emollient. Emollients help soften and soothe our skin by creating a barrier on top. This barrier helps trap moisture in, keeping skin hydrated.

It is created using either the hydrogenation or transesterification processes on jojoba oil.

Leuconostoc/Radish Root Ferment Filtrate is a natural preservative. It comes from fermenting radish roots with a bacteria called leuconostoc. The trade name for this ingredient is Leucidal.

Leuconostoc comes from lactic acid.

This ingredient has antimicrobial properties and helps prevent the growth of bacteria in a product.

Leuconostoc is used to make the traditional Korean side-dish, kimchi. It is also used to make sourdough bread (both incredibly yummy foods).

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.

Polysorbate 20 is a gentle, water-soluble emulsifier and mild surfactant. It stops oil and water from separating to keep your formulas blended and stable.

It also acts as a mild penetration enhancer by helping active ingredients absorb slightly better.

The common safety discussion around this ingredient involves a manufacturing byproduct called 1,4-dioxane.

Trace amounts can form during production but the EU's Scientific Committee on Consumer Safety has concluded that levels at/below 10 ppm in finished products are safe (commercial products consistently fall within acceptable margins).

True allergic reactions are uncommon and the CIR Expert Panel has confirmed this ingredient to be safe as used in cosmetics.

Because it is derived from lauric acid, it may not be fungal acne safe.

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 Benzoate is a preservative. It's used in both cosmetic and food products to inhibit the growth of mold and bacteria. It is typically produced synthetically.

Both the US FDA and EU Health Committee have approved the use of sodium benzoate. In the US, levels of 0.1% (of the total product) are allowed.

Sodium benzoate works as a preservative by inhibiting the growth of bacteria inside of cells. It prevents the cell from fermenting a type of sugar using an enzyme called phosphofructokinase.

It is the salt of benzoic acid. Foods containing sodium benzoate include soda, salad dressings, condiments, fruit juices, wines, and snack foods.

Studies for using ascorbic acid and sodium benzoate in cosmetics are lacking, especially in skincare routines with multiple steps.

We always recommend speaking with a professional, such as a dermatologist, if you have any concerns.

Sorbitan Isostearate is an emulsifer. It is created from isostearic acid and sorbitol.

As an emulsifier, it keeps the water and oil ingredients from separating. This keeps formulas stable and smooth.

In a 24 hour occlusive patch test on 56 subjects, 10% sorbitan isostearate was completely non-irritating. Most formulas use less than 10%.

Because it's a fatty acid ester, it may not be fungal acne safe since the Malassezia yeast can utilize it as a nutrient source.

Tocopherol is a fat-soluble antioxidant known as Vitamin E.

You'll find this ingredient in the vast majority of skincare (for good reason). It works to neutralize free radicals, or unstable molecules generated by UV exposure, pollution, and other environmental stressors, before they can cause oxidative damage to your skin cells.

Topically applied tocopherol has been shown to protect against UV damage by ramping up the skin's own natural defense enzymes.

It also acts as a skin conditioning agent; some studies show that regular topical use can improve the skin's water-binding capacity over 2-4 weeks.

This ingredient is especially loved for being a team player. When combined with Vitamin C, the photoprotective effect of both ingredients roughly doubles and the combo also helps reduce UV-induced DNA damage.

This ingredient has some brightening potential but it's more of a prevention ingredient than spot-fader. Cell studies show it can slow down melanin production but it's worth noting that it's not the most powerful brightener out there.

In formulations, it also serves as a stabilizer that helps protect other oxidation-prone ingredients from degrading.

Concentrations usually range from 0.1-1% in most leave-on products.

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 Explained

  1. 01These ingredients are found in both products.
  2. 02Ingredients higher up in an ingredient list are typically present in a larger amount.
  3. 03Gluconolactone is a PHA. PHAs are a great gentle alternative to traditional AHAs.
  4. 04When applied, Gluconolactone has the same affect on skin as AHAs such as lactic acid. It helps dissolve the dead skin cells in the top layer of your skin. This improves texture and brightens the skin.
  5. 05PHAs are more gentle than AHAs due to their larger structure. They do not penetrate as deeply as AHAs and take a longer time to dissolve dead cells. Studies show PHAs do not cause as much irritation.
  6. 06Gluconolactone has some interesting properties:
  7. 07In a 2004 study, Gluconolactone was found to prevent UV damage in mouse skin cells and has not been found to increase sun sensitivity. However, we still recommend wearing SPF daily.
  8. 08This ingredient is is an created by reacting gluconic acid with an alcohol.
  9. 09Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.
  10. 10Topically, glycerin does several things at once:
  11. 11Your 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.
  12. 12Aquaporin-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.
  13. 13This 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.
  14. 14Just know very high concentrations (>40%) can feel tacky in low humidity.
  15. 15Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.
  16. 16Propanediol is an all-star ingredient. It softens, hydrates, and smooths the skin.
  17. 17It’s often used to:
  18. 18Propanediol 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.
  19. 19Sodium 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.
  20. 20In small amounts, sodium hydroxide is considered safe to use. However, large amounts may cause chemical burns due to its high alkaline.
Source · skinsort.com
02

Product index

Related product references

03

Comparison edit

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