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Skin science article

COSRX The Retinol 0.5 Oil Versus The INKEY List Retinol Serum

COSRX The Retinol 0.5 Oil Versus The INKEY List Retinol Serum This anti-aging oil is formulated around Retinol and Squalane to soften the look of wrinkles and refine skin texture. This anti-aging serum is formulated around Retinyl Acetate and Palmitoyl Tetrape

COSRX The Retinol 0.5 Oil Versus The INKEY List Retinol Serum

This anti-aging oil is formulated around Retinol and Squalane to soften the look of wrinkles and refine skin texture.

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

Squalane

Glycine Soja Oil

Di-C12-13 Alkyl Malate

Retinol

Caprylic/Capric Triglyceride

BHT

Tocotrienols

Tocopherol

Elaeis Guineensis Oil

Hydroxymethoxyphenyl Decanone

Squalane, Glycine Soja Oil, Di-C12-13 Alkyl Malate, Retinol, Caprylic/Capric Triglyceride, BHT, Tocotrienols, Tocopherol, Elaeis Guineensis Oil, Hydroxymethoxyphenyl Decanone

Water

Glycerin

Butylene Glycol

Propanediol

Dicaprylyl Carbonate

Retinyl Acetate

Dimethicone

Phenoxyethanol

Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer

Caprylyl Glycol

Phospholipids

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

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.

Glycine Soja Oil is a plant-derived oil from soybean seeds. Like other oils, it is rich in essential fatty acids (mostly linoleic and oleic) that support skin hydration and barrier function.

The fatty acids are able to integrate into the lipid matrix of the stratum corneum to help soften skin and reduce water loss.

On top of that, soybean oil is rich in vitamins like vitamin E, a potent antioxidant.

Research on soybean's active components also point to anti-inflammatory, collagen-stimulating, antioxidant activity, and protection against UV-induced oxidative damage.

Most of this research applies to the broader soybean plant and not just the oil fraction alone.

This ingredient may not be fungal acne safe due to the oleic acid content.

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.

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.

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. 03Alanine is an amino acid and is already found in the human body. Our skin uses alanine to build collagen, elastin, and keratin.
  4. 04Arginine is a semi-essential amino acid. This just means our bodies can product a bit on its own, but sometimes needs a little boost from food sources.
  5. 05It is a part of your skin's natural moisturizing factor (NMF), or the water-loving molecules in your outermost layer of skin (stratum corneum) that keeps everything hydrated and happy.
  6. 06Here's an interesting thing about Arginine: your skin converts it into urea through the Krebs-Henseleit urea cycle. Urea is one of the most effective humectants your skin naturally produces.
  7. 07A clinical study showed applying 2.5% arginine hydrochloride to atopic dermatitis skin showed significant urea levels in the stratum corneum and improved moisture in just four weeks.
  8. 08Arginine is also a precursor to nitric oxide; nitric oxide improves microcirculation and supports wound healing and collagen synthesis.
  9. 09One study found that an amino acid complex containing Arginine reduced skin irritation, improved hydration, and accelerated skin repair in clinical / in-vivo studies.
  10. 10Arginine itself is an amino acid and not a fatty acid, oil, or ester. On its own, it's not a direct food source for Malassezia, or the yeast that causes fungal acne.
  11. 11Aspartic Acid is an amino acid that our bodies produce naturally. It is an antioxidant.
  12. 12Our body uses Aspartic Acid to help build collagen and elastin. It also plays a role in hydrating skin.
  13. 13Benzyl Alcohol is an aromatic alcohol with several roles: it's a preservative, solvent, and mild fragrance component with a floral scent.
  14. 14This 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.
  15. 15As a preservative, it works by disrupting the membrane of microbial proteins. This helps keep bacteria and fungi from growing in your products.
  16. 16The 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.
  17. 17This led researchers to conclude that benzyl alcohol cannot be regarded as a significant contact allergen.
  18. 18It is worth noting this ingredient is classified as one of the EU's regulated fragrance allergens and restricted to 1% in finished products.
  19. 19Labels must also declare it in concentrations above 0.001% in leave-on products and 0.01% in rinse-off products.
  20. 20At concentrations around 5%, localized redness and itching can appear as a direct irritant response and not as a true allergic reaction.
Source · skinsort.com
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Product index

Related product references

Product

The Inkey List Multi-Biotic

The Inkey List Multi-Biotic The Inkey List Multi-Biotic ingredients explained: Water (Aqua/Eau), Inulin, Glycerin, Isoamyl Laurate, Propanediol, Squalane, Cetearyl Olivate, Sorbitan Olivate…

Source: incidecoder.comView reference →
03

Comparison edit

Read side by side