The INKEY List Polyglutamic Acid Hydrating Serum Versus The Ordinary Hyaluronic Acid 2% + B5

The INKEY List Polyglutamic Acid Hydrating Serum Versus The Ordinary Hyaluronic Acid 2% + B5

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

This hydrating treatment is formulated around Sodium Hyaluronate and Sodium Hyaluronate Crosspolymer to hydrate skin and strengthen the skin barrier.

What's inside

Key Ingredients

No key ingredients

Benefits

Concerns

No concerns

Ingredients Side-by-side

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

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

Sodium Hyaluronate

Pentylene Glycol

Sodium Hyaluronate Crosspolymer

Panthenol

Ahnfeltia Concinna Extract

Citric Acid

Isoceteth-20

Ethoxydiglycol

1,2-Hexanediol

Water, Sodium Hyaluronate, Pentylene Glycol, Propanediol, Sodium Hyaluronate Crosspolymer, Panthenol, Ahnfeltia Concinna Extract, Glycerin, Trisodium Ethylenediamine Disuccinate, Citric Acid, Isoceteth-20, Ethoxydiglycol, Ethylhexylglycerin, Hexylene Glycol, 1,2-Hexanediol, Phenoxyethanol, Caprylyl Glycol

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.

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).

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.

Hexylene Glycol is a multitasker ingredient that works as a solvent, humectant, emulsifier, viscosity reducer, and preservative booster.

It is able to dissolve both water and oil-soluble ingredients to stabilize tricky actives and make products spread more easily.

As a humectant, it pulls water into the skin. But it's a pretty minor moisturizing ingredient compared to other humectants, like glycerin.

Interestingly, it can act as a mild penetration enhancer. One in vitro study on human skin found a 12% concentration upped the absorption of mometasone furoate (a medicinal ingredient used to treat inflammatory skin conditions) up to 7%.

This ingredient is typically used at levels of 0.1-10% depending on the role it's playing.

A patch test study on eczema patients didn't find a significant increase in irritation versus the control group, but the potential for irritation rises at higher concentrations.

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.

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.

Trisodium Ethylenediamine Disuccinate is used to help stabilize a product.

It is a chelating agent, meaning it helps prevent metal ions from binding to other ingredients. This prevents unwanted reactions in products. Metal ions can come into a product via the water ingredient. They are found in trace amounts and are not known to be harmful.

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!

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