Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

The INKEY List Retinol Eye Cream Versus The INKEY List Caffeine Eye Cream

The INKEY List Retinol Eye Cream Versus The INKEY List Caffeine Eye Cream This anti-aging eye moisturizer is formulated around Retinol and Sodium Hyaluronate to soften the look of wrinkles and refine skin texture. This anti-aging eye moisturizer is formulated

The INKEY List Retinol Eye Cream Versus The INKEY List Caffeine Eye Cream

This anti-aging eye moisturizer is formulated around Retinol and Sodium Hyaluronate to soften the look of wrinkles and refine skin texture.

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

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Caprylic/Capric Triglyceride

Glycerin

Butylene Glycol

Pentaerythrityl Distearate

Shea Butter Ethyl Esters

Cetearyl Olivate

Phenoxyethanol

Benzyl Alcohol

Sorbitan Olivate

Acrylates/C10-30 Alkyl Acrylate Crosspolymer

Sodium Hydroxide

Sodium Hyaluronate

Sodium Stearoyl Glutamate

Copernicia Cerifera Cera

Propanediol

Glycogen

Sodium Gluconate

Retinol

Polysorbate 20

Ethylhexylglycerin

Dehydroacetic Acid

Citric Acid

Helianthus Annuus Seed Oil

1,2-Hexanediol

Caprylyl Glycol

Disodium Cocoamphodiacetate

Tocopherol

Xanthan Gum

Ethyl Ferulate

Humulus Lupulus Extract

Water, Caprylic/Capric Triglyceride, Glycerin, Butylene Glycol, Pentaerythrityl Distearate, Shea Butter Ethyl Esters, Cetearyl Olivate, Phenoxyethanol, Benzyl Alcohol, Sorbitan Olivate, Acrylates/C10-30 Alkyl Acrylate Crosspolymer, Sodium Hydroxide, Sodium Hyaluronate, Sodium Stearoyl Glutamate, Copernicia Cerifera Cera, Propanediol, Glycogen, Sodium Gluconate, Retinol, Polysorbate 20, Ethylhexylglycerin, Dehydroacetic Acid, Citric Acid, Helianthus Annuus Seed Oil, 1,2-Hexanediol, Caprylyl Glycol, Disodium Cocoamphodiacetate, Tocopherol, Xanthan Gum, Ethyl Ferulate, Humulus Lupulus Extract

Dicaprylyl Carbonate

Polyglyceryl-6 Distearate

Cetyl Alcohol

Glyceryl Behenate

Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer

Jojoba Esters

Albizia Julibrissin Bark Extract

Squalane

Caffeine

Polyglyceryl-3 Beeswax

Phospholipids

Glycine Soja Oil

Polysorbate 60

Sodium Phytate

Glycolipids

Sorbitan Isostearate

Glycine Soja Sterols

Leuconostoc/Radish Root Ferment Filtrate

Hyaluronic Acid

Sodium Benzoate

Carbomer

Darutoside

Sodium Lactate

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

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.

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.

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.

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 Side-by-side

  1. 01Water
  2. 02Dimethicone
  3. 03Butylene Glycol
  4. 04Bis-PEG-12 Dimethicone
  5. 05Glycerin
  6. 06Polymethylsilsesquioxane
  7. 07Polysilicone-11
  8. 08Phenoxyethanol
  9. 09Polyglutamic Acid
  10. 10Sodium Acrylate/Sodium Acryloyldimethyl Taurate Copolymer
  11. 11Isohexadecane
  12. 12Propanediol
  13. 13Coco-Glucoside
  14. 14Sodium Benzoate
  15. 15Hydroxyethylcellulose
  16. 16Polysorbate 80
  17. 17Ethylhexylglycerin
  18. 18Potassium Sorbate
  19. 19Decyl Glucoside
  20. 20Dimethylacrylamide/Acrylic Acid/Polystyrene Ethyl Methacrylate Copolymer
Source · skinsort.com
02

Product index

Related product references

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The Inkey List Multi-Biotic

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Source: incidecoder.comView reference →

Product

The Inkey List Brighten-i Eye Cream

The Inkey List Brighten-i Eye Cream The Inkey List Brighten-i Eye Cream ingredients explained: Water (Aqua/Eau), Dimethicone, Coco-Caprylate/Caprate, Glycerin, Caprylic/Capric Triglyceride,…

Source: incidecoder.comView reference →
03

Comparison edit

Read side by side