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Skin science article

Paula's Choice 1% Retinol Treatment Versus The INKEY List Polyglutamic Acid Hydrating Serum

Paula's Choice 1% Retinol Treatment Versus The INKEY List Polyglutamic Acid Hydrating Serum This anti-aging treatment is formulated around Retinol and Tetrahexyldecyl Ascorbate to soften the look of wrinkles and refine skin texture. This hydrating serum is for

Paula's Choice 1% Retinol Treatment Versus The INKEY List Polyglutamic Acid Hydrating Serum

This anti-aging treatment is formulated around Retinol and Tetrahexyldecyl Ascorbate to soften the look of wrinkles and refine skin texture.

This hydrating serum is formulated around Polyglutamic Acid to hydrate skin and strengthen the skin barrier.

What's inside

Key Ingredients

No key ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Dimethicone

Glycerin

Butylene Glycol

Isononyl Isononanoate

Castor Isostearate Succinate

Glyceryl Stearate

C12-15 Alkyl Benzoate

Dimethicone Crosspolymer

PEG-33

Polysorbate 20

Behenyl Alcohol

PEG-100 Stearate

Pentaerythrityl Tetraisostearate

Polymethylsilsesquioxane

Tetrahexyldecyl Ascorbate

Retinol

Ceramide Ng

Palmitoyl Tetrapeptide-7

Palmitoyl Hexapeptide-12

Sodium Hyaluronate

Dipotassium Glycyrrhizate

Glycyrrhiza Glabra Root Extract

Avena Sativa Kernel Extract

Arctium Lappa Seed Oil

Salix Alba Extract

Glycine Soja Sterols

Lecithin

Allantoin

Tocopheryl Acetate

Hydrolyzed Soy Protein

Sorbitan Laurate

Acetyl Dipeptide-1 Cetyl Ester

Disodium EDTA

Hydroxyethylcellulose

Palmitoyl Tripeptide-1

Sodium Hydroxide

Tribehenin

Caprylyl Glycol

Ethylhexylglycerin

Pentylene Glycol

PEG-75 Shea Butter Glycerides

PPG-12/Smdi Copolymer

PEG-10 Phytosterol

PEG-8 Dimethicone

PEG-14

Magnesium Aluminum Silicate

Arachidyl Glucoside

Arachidyl Alcohol

Sclerotium Gum

Carbomer

Phenoxyethanol

Benzoic Acid

Water, Dimethicone, Glycerin, Butylene Glycol, Isononyl Isononanoate, Castor Isostearate Succinate, Glyceryl Stearate, C12-15 Alkyl Benzoate, Dimethicone Crosspolymer, PEG-33, Polysorbate 20, Behenyl Alcohol, PEG-100 Stearate, Pentaerythrityl Tetraisostearate, Polymethylsilsesquioxane, Tetrahexyldecyl Ascorbate, Retinol, Ceramide Ng, Palmitoyl Tetrapeptide-7, Palmitoyl Hexapeptide-12, Sodium Hyaluronate, Dipotassium Glycyrrhizate, Glycyrrhiza Glabra Root Extract, Avena Sativa Kernel Extract, Arctium Lappa Seed Oil, Salix Alba Extract, Glycine Soja Sterols, Lecithin, Allantoin, Tocopheryl Acetate, Hydrolyzed Soy Protein, Sorbitan Laurate, Acetyl Dipeptide-1 Cetyl Ester, Disodium EDTA, Hydroxyethylcellulose, Palmitoyl Tripeptide-1, Sodium Hydroxide, Tribehenin, Caprylyl Glycol, Ethylhexylglycerin, Pentylene Glycol, PEG-75 Shea Butter Glycerides, PPG-12/Smdi Copolymer, PEG-10 Phytosterol, PEG-8 Dimethicone, PEG-14, Magnesium Aluminum Silicate, Arachidyl Glucoside, Arachidyl Alcohol, Sclerotium Gum, Carbomer, Phenoxyethanol, Benzoic Acid

Bis-PEG-12 Dimethicone

Polysilicone-11

Polyglutamic Acid

Sodium Acrylate/Sodium Acryloyldimethyl Taurate Copolymer

Isohexadecane

Propanediol

Coco-Glucoside

Sodium Benzoate

Polysorbate 80

Potassium Sorbate

Decyl Glucoside

Dimethylacrylamide/Acrylic Acid/Polystyrene Ethyl Methacrylate Copolymer

Sorbitan Oleate

Trisodium Ethylenediamine Disuccinate

Hexylene Glycol

Oryza Sativa Bran Extract

Water, Dimethicone, Butylene Glycol, Bis-PEG-12 Dimethicone, Glycerin, Polymethylsilsesquioxane, Polysilicone-11, Phenoxyethanol, Polyglutamic Acid, Sodium Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Isohexadecane, Propanediol, Coco-Glucoside, Sodium Benzoate, Hydroxyethylcellulose, Polysorbate 80, Ethylhexylglycerin, Potassium Sorbate, Decyl Glucoside, Dimethylacrylamide/Acrylic Acid/Polystyrene Ethyl Methacrylate Copolymer, Sorbitan Oleate, Trisodium Ethylenediamine Disuccinate, Caprylyl Glycol, Hexylene Glycol, Oryza Sativa Bran Extract

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.

Caprylyl Glycol is a humectant, skin conditioner, emollient, and preservative booster derived from either caprylic acid or synthetically created.

Typical use levels vary from 0.3-1% as a preservative booster and go up to 2% to condition skin.

Because it is not a free-fatty acid, this ingredient is fungal acne safe (there's nothing for Malassezia to feed on).

Dimethicone is a type of synthetic silicone created from natural materials such as quartz. It is also known as polydimethylsiloxane.

What it does:

Dimethicone comes in different viscosities:

Depending on the viscosity, dimethicone has different properties.

Ingredients lists don't always show which type is used, so we recommend reaching out to the brand if you have questions about the viscosity.

This ingredient is unlikely to cause irritation because it does not get absorbed into skin. However, people with silicone allergies should be careful about using this ingredient.

Note: Dimethicone may contribute to pilling. This is because it is not oil or water soluble, so pilling may occur when layered with products. When mixed with heavy oils in a formula, the outcome is also quite greasy.

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.

Hydroxyethylcellulose is used to improve the texture of products. It is created from a chemical reaction involving ethylene oxide and alkali-cellulose. Cellulose is a sugar found in plant cell walls and help give plants structure.

This ingredient helps stabilize products by preventing ingredients from separating. It can also help thicken the texture of a product.

This ingredient can also be found in pill medicines to help our bodies digest other ingredients.

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.

Polymethylsilsesquioxane is a silicone used as a film forming agent.

When applied to the skin, this ingredient creates an invisible film on the surface. This film still allows oxygen to pass through, but prevents moisture from escaping. This can help condition and hydrate the skin. It also leaves a silky feel when applied.

Polymethylsilsesquioxane has not been shown to clog pores. It has been deemed safe to use up to 55%, but most cosmetics use much less.

If you have concerns about using this ingredient, we recommend speaking with a professional.

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.

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. 03Ethylhexylglycerin is created from glycerin. It is a multitasker ingredient that:
  4. 04The 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 …
  5. 05Industry-reported use ranges from 8% in rinse-off products and 2% in leave-on formulations.
  6. 06Phenoxyethanol is one of the most widely used preservatives in skincare (and for good reason!).
  7. 07It 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.
  8. 08On 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.
  9. 09Another perk of this ingredient is that it stays functional across a wide pH range (3-10).
  10. 10You'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.
  11. 11Typical use concentrations range from 0.3-1% depending on the formula, and this ingredient is capped at 1% int the EU.
  12. 12Safety-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.
  13. 13Adverse 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.
  14. 14Chances are, you eat sodium chloride every day. Sodium Chloride is also known as table salt. This ingredient has many purposes in skincare: thickener, emulsifier, and exfoliator.
  15. 15You'll most likely find this ingredient in cleansers where it is used to create a gel-like texture. As an emulsifier, it also prevents ingredients from separating.
  16. 16You might see people debate whether Sodium Chloride is comedogenic, but there actually haven't been any comedogenic tests done on it. Either way, the overall formulation of a product matters a lot more than any single ingredient.
  17. 17You might see this ingredient used in scrubs as a primary exfoliating ingredient.
  18. 18Water. 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.
  19. 19So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.
  20. 20You'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!
Source · skinsort.com
02

Product index

Related product references

03

Comparison edit

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