Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

Trader Joe's Supreme Hydrating Eye Cream Versus The INKEY List Retinol Serum

Trader Joe's Supreme Hydrating Eye Cream Versus The INKEY List Retinol Serum This barrier-repair eye moisturizer is formulated around Butyrospermum Parkii Butter and Squalane to strengthen the skin barrier and hydrate skin. This anti-aging serum is formulated

Trader Joe's Supreme Hydrating Eye Cream Versus The INKEY List Retinol Serum

This barrier-repair eye moisturizer is formulated around Butyrospermum Parkii Butter and Squalane to strengthen the skin barrier and hydrate skin.

This anti-aging serum is formulated around Retinyl Acetate and Palmitoyl Tetrapeptide-7 to soften the look of wrinkles and refine skin texture.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Dicaprylyl Carbonate

Betaine

Glycerin

Cetearyl Alcohol

Prunus Amygdalus Dulcis Oil

Cetyl Alcohol

Cetearyl Olivate

Isopropyl Myristate

Isoamyl Laurate

Sorbitan Olivate

Glyceryl Caprylate

Butyrospermum Parkii Butter

Triethanolamine

Argania Spinosa Kernel Oil

Sclerocarya Birrea Seed Oil

Carbomer

Honey

Parfum

Caprylhydroxamic Acid

Tocopheryl Acetate

Sodium Citrate

Rosa Canina Seed Oil

Hydrolyzed Collagen

Squalane

Cassia Angustifolia Seed Polysaccharide

Hydrolyzed Hibiscus Esculentus Extract

Dextrin

Ubiquinone

Water, Dicaprylyl Carbonate, Betaine, Glycerin, Cetearyl Alcohol, Prunus Amygdalus Dulcis Oil, Cetyl Alcohol, Cetearyl Olivate, Isopropyl Myristate, Isoamyl Laurate, Sorbitan Olivate, Glyceryl Caprylate, Butyrospermum Parkii Butter, Triethanolamine, Argania Spinosa Kernel Oil, Sclerocarya Birrea Seed Oil, Carbomer, Honey, Parfum, Caprylhydroxamic Acid, Tocopheryl Acetate, Sodium Citrate, Rosa Canina Seed Oil, Hydrolyzed Collagen, Squalane, Cassia Angustifolia Seed Polysaccharide, Hydrolyzed Hibiscus Esculentus Extract, Dextrin, Ubiquinone

Butylene Glycol

Propanediol

Retinyl Acetate

Dimethicone

Phenoxyethanol

Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer

Caprylyl Glycol

Phospholipids

Glycine Soja Oil

Polysorbate 60

Glycolipids

Sodium Hydroxide

Sodium Phytate

Sorbitan Isostearate

Glycine Soja Sterols

Tetrahexyldecyl Ascorbate

Leuconostoc/Radish Root Ferment Filtrate

Hyaluronic Acid

Sodium Lactate

Tocopherol

Polysorbate 20

Palmitoyl Tetrapeptide-7

Palmitoyl Tripeptide-1

Water, Glycerin, Butylene Glycol, Propanediol, Dicaprylyl Carbonate, Retinyl Acetate, Dimethicone, Phenoxyethanol, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Caprylyl Glycol, Phospholipids, Squalane, Glycine Soja Oil, Carbomer, Polysorbate 60, Tocopheryl Acetate, Glycolipids, Sodium Hydroxide, Sodium Phytate, Sorbitan Isostearate, Glycine Soja Sterols, Tetrahexyldecyl Ascorbate, Leuconostoc/Radish Root Ferment Filtrate, Hyaluronic Acid, Sodium Lactate, Tocopherol, 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.

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.

Dicaprylyl Carbonate comes from carbonic acid and caprylyl alcohol, a fatty alcohol. It is an emollient and gives skin a velvet feel. The sources of Dicaprylyl Carbonate may be synthetic or from animals.

As an emollient, Dicaprylyl Carbonate creates a film on the skin. This film traps moisture in, keeping your skin soft and hydrated.

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.

Squalane is the hydrogenated and shelf-stable form of squalene (a lipid that naturally occurs in human sebum).

It is an emollient and skin conditioning agent that is able to integrate seamlessly into the skin's lipid barrier without clogging pores.

This is due to how structurally similar it is to what your skin already produces.

Though it is mostly an emollient that helps soften and hydrate skin, it also has some humectant and occlusive action. Humectants help the skin retain moisture while occlusives seal it in, making squalane a triple-threat moisturizer.

Research shows it has antioxidant capabilities that help protect against stressors like UV exposure, specifically UVA induced oxidative stress. This study also found that it supports collagen biosynthesis in human dermal fibroblasts.

No clinical study has reported significant adverse effects and irritation reactions are very rare from this ingredient (even at 100% concentration).

Overall, it's a fantastic ingredient for hydration and is suitable for all skin types.

This depends on the source. Squalane can be derived from both plants and animals. Most squalane used in skincare comes from plants.

Please note: the source of squalane is only known if disclosed by the brand. We recommend reaching out to the brand if you have any questions about their squalane.

Read more about squalene with an "e".

Though squalane is often called an oil, it’s technically not one. It is a hydrocarbon, meaning it is only made of carbon and hydrogen. True oils are triglycerides and made of fatty acids and glycerol.

The term “oil-free” isn’t regulated so companies can define it however they want. Some exclude all oils, while others just avoid mineral oil or comedogenic oils.

Squalane has a comedogenic rating of 1 from the original 1972 study that tested raw ingredients under occlusion on rabbit ears. This system is not standardized or peer-reviewed, and using the raw ingredients is very different from how diluted cosmetic formulations are used on human skin.

A comedogenic rating of 1 means it is "unlikely to clog pores" according to the original rating system.

The overall formula of a product matters more than the individual ingredients on whether or not it will cause clogged pores.

Tocopheryl Acetate is a stable, shelf-friendly form of vitamin E.

Formulators love it because plain vitamin E oxidizes quickly once it hits air. This acetate version stays stable and resists going off, helping to extend a product's shelf life.

It's actually inactive on its own and works like a slow-release "storage" form; the enzymes in your skin called esterases gradually convert it into active vitamin E over time.

One in vivo study showed 5% of the acetate in the living layer of the epidermis converted to vitamin E after 5 days of application. This study also found the skin gained protection against UV damage even though the conversion was slow and small.

Once converted, vitamin E acts as a skin's main fat-soluble antioxidant that fights free radicals to protect skin from damage.

Topical vitamin E generally boosts the skin's photoprotection, and it reduced UV-damage in animal models.

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.

Overall, it has a pretty solid safety profile and has been found to be non-irritating and non-comedogenic. Allergic reactions may happen but stay rare due to how widely the ingredient gets used.

The concentration will vary depending on the formula; industry data shows 0.1% in baby lotions, 3% in lipsticks, and 5% in foot powders. You can also find this ingredient at 100% in a pure vitamin E oil.

Most leave-on skincare keeps it at the lower end, often between 0.5-1%.

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.

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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. 03Hyaluronic acid (HA) is a glycosaminoglycan (basically a long sugar chain) that your skin already makes on its own. In your skin, HA lives in the extracellular matrix and acts as the body's moisture reservoir.
  4. 04Topically, HA is a humectant that binds water and helps skin look more plump, smooth, and hydrated.
  5. 05The only catch is that HA isn't a single thing; it actually comes in a wide range of molecular weights (~50 - 2,000+ kDA) and size matters.
  6. 06Some clinical evidence links low molecular weight versions to improved wrinkle depth, elasticity, anti-inflammatory effects, and barrier repair.
  7. 07This is why the best HA serums blend the two sizes together so you get the best of both worlds.
  8. 08The majority of cosmetic HA is produced by bacterial fermentation, typically using Streptococcus or Bacillus strains. Typical use levels in skincare sit around 0.1-2%.
  9. 09A clinical study using a 0.2% low-molecular weight HA gel showed improvement in facial seborrheic dermatitis with excellent tolerance.
  10. 10These are some other common types of Hyaluronic Acid:
  11. 11Propanediol is an all-star ingredient. It softens, hydrates, and smooths the skin.
  12. 12It’s often used to:
  13. 13Propanediol 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.
  14. 14Ubiquinone (Coenzyme Q10) is a molecule already found in our bodies. It is a potent antioxidant and skin-soothing ingredient.
  15. 15Aging and environmental exposure diminishes our skin's natural ubiquinone levels. This is much like our natural collagen and elastin.
  16. 16The good news is: studies show applying this ingredient topically replenishes ubiquinone levels in our skin. This also comes with a ton of skin benefits. These benefits include:
  17. 17Ubiquinone is considered a large molecule and cannot be absorbed into the lower layers of skin. This is why it is believed to be such an effective antioxidant: it protects our skin in the upper layers and prevents damage in the deeper layers.
  18. 18When used in sunscreen, ubiquinone is shown to increase ingredient stability, increase SPF factor, and add to infrared protection.
  19. 19Fun fact: ubiquinone is fat-soluble.
  20. 20Water. 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.
Source · skinsort.com
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Product index

Related product references

Product

The Inkey List Starter Retinol Serum

The Inkey List Starter Retinol Serum The Inkey List Starter Retinol Serum ingredients explained: Water (Aqua/Eau), Glycerin, Dicaprylyl Carbonate, Propanediol, Candelilla/Jojoba/Rice Bran P…

Source: incidecoder.comView reference →
03

Comparison edit

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