Polyglutamic Acid Serum

Inkey List

Polyglutamic Acid Serum

Polyglutamic Acid Serum

Inkey List

polyglutamic-acid-serum

Serum

9784791957797

Morning or Evening?

Morning
Evening
Both

How often will you use this product?

Everyday
Every other day
Every 3 days
Every 4 days
Every 5 days
Every 6 days
Once a week
Twice a week
On specific days
As needed
On rotation

Notes

Add to Routine
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Compatibility Score

0%

Microbiome
Ingredients
Biological
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How It Fits Into Your Skincare Routine

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Highlights

WHAT IS IT?

Hydrating serum with 3% Polyglutamic Acid

FEATURES

4x more moisture holding capacity than Hyaluronic Acid, Smoothing effect, Brightening properties

BEST FOR

combination

CHECKS

Free of parabens, phthalates, sulfates, synthetic fragrances, gluten

Who Is It For?

All Ages All Genders

What Does It Help With?

Hydration Fine Lines Skin Tone Evening Skin Smoothing

Budget

Affordable (under $30)

How To Use

Which routine should it be used in?

Morning
Evening
 
Cleanse
Tone
Eyecare
Serum
Moisturize
Suncare
 

Instructions:

Apply a pea-sized amount AM and PM

Key Information

Vegan
Cruelty-free
Sensitive-safe
Non-comedogenic
Hypoallergenic
Microbiome-safe
Preservative-free
Eco-friendly
Pregnancy-safe
Oil-free

What Inkey List Says

Product Description:

A powerful hydrator for the skin's surface, Polyglutamic Acid can hold 4x more moisture than Hyaluronic Acid, locking in moisture and helping the skin appear instantly smoother. This 3% high molecular weight amino polymer is specifically designed to enhance skin moisturization on the surface. This smoothing serum helps to reduce the appearance of fine lines, as well as brighten and even skin tone. The lightweight silky texture creates a perfect make-up canvas.

About the Brand:

Democratizing skincare knowledge and ingredients, The INKEY List offers straightforward, single-ingredient-focused products at accessible price points. Founded in 2018 by Colette Laxton and Mark Curry, this educational brand demystifies skincare through transparency and simplicity. Experience high-performance actives without confusing formulations or premium pricing, supported by straightforward guidance for building personalized routines.

Ingredients Overview

Ingredients List

Aqua (water), Dimethicone, Butylene glycol, Bis-peg-12 dimethicone, Glycerin, Polymethylsilsesquioxane, Polysilicone-11, Polyglutamic acid, Phenoxyethanol, 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 (rice) bran extract

Key Ingredients

polyglutamic-acid

Ingredients Details

Bis-peg-12 Dimethicone

Common Name(s): Bis-peg-12 dimethicone

DESCRIPTION

What It Does: Reduces surface tension at oil-water interfaces, enabling effective cleansing, emulsification, and formulation stability.

Why It's Used: Surface-active agents are essential for emulsification, cleansing, and stabilization of cosmetic formulations containing both aqueous and lipid phases.

How It Works: The amphiphilic molecular structure positions the hydrophilic head in water and the lipophilic tail in oils, creating micelles that solubilize sebum, dirt, and oil-soluble impurities for rinsing in cleansers or stable emulsions in leave-on products.

Typically Found In: Cleansers,shampoos,body washes,foaming treatments

TECHNICAL DETAILS

Primary Category: Surfactants

Secondary Functions: Emulsifying,cleansing

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.5โ€“30%

SOURCING & ETHICS

Vegan Status: Yes

Halal Status: Yes

Source Notes: Synthetic or semi-synthetic surfactant; no animal components.

SKIN COMPATIBILITY

Irritancy Rating: 2

Comedogenicity Rating: 0

Sensitivity Concerns: May cause irritation or stinging in sensitive or barrier-compromised skin at high concentrations; patch test recommended.

Safe for Sensitive Skin: Conditional

SAFETY & COMPATIBILITY

Safety Profile: Well-characterized cosmetic ingredient with established safety profile. mildly irritating to some individuals at typical use concentrations. suitable for leave-on and rinse-off cosmetics.

Works Well With: Other surfactants,thickeners,conditioning agents

Avoid Combining With: High concentrations in sensitive skin formulations

SCIENTIFIC NOTE

Surfactant critical micelle concentration (cmc) determines the threshold for emulsification: above the cmc, amphiphilic molecules self-assemble into micelles with hydrophobic cores that solubilize oils. hlb (hydrophile-lipophile balance) value predicts surfactant function: hlb 3โ€“6 for w/o emulsifiers, 8โ€“18 for o/w emulsifiers, >15 for solubilizers.

Last Verified: Cosing eu database; pcpc cosmetic ingredient safety reviews; ingredient-specific safety and efficacy literature

Primary Sources: 2025-01-15

Butylene Glycol

Common Name(s): 1,3-butanediol,bg,1,3-butylene glycol

CAS Number: 107-88-0

DESCRIPTION

What It Does: Provides humectant hydration and active ingredient solubilization with excellent skin feel.

Why It's Used: Preferred glycol humectant in premium and k-beauty formulations for superior skin feel vs propylene glycol with equivalent functionality.

How It Works: Two hydroxyl groups at 1,3-positions provide water binding and solvent activity. better tolerated than propylene glycol with minimal sensitization risk. 4-carbon backbone provides slightly greater hydrophobic character enabling dissolution of less polar actives vs pg.

Typically Found In: Toners,essences,serums,k-beauty formulas

TECHNICAL DETAILS

Primary Category: Functional ingredient โ€“ glycol humectant

Secondary Functions: Tewl reduction,skin plumping

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 1%โ€“10%

SOURCING & ETHICS

Vegan Status: Yes โ€“ synthetic

Halal Status: Yes

Source Notes: Synthetic or naturally derived. excellent aqueous solubility.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 โ€“ very low

Comedogenicity Rating: 0/5 โ€“ non-comedogenic

Sensitivity Concerns: Non-irritating; suitable for all skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Excellent safety profile. ewg score: 1.

Works Well With: Ceramides,emollients,occlusives,glycerin,hyaluronic acid

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

K-beauty's preference for butylene glycol over propylene glycol is driven by two factors: bg's superior skin feel (less tacky than pg's higher viscosity) and its lower sensitization potential (1,3-bg has better spatial distribution of hydroxyl groups that reduces protein interaction vs pg's 1,2-position oh groups).

Last Verified: Cosing database,cir safety assessment

Primary Sources: 2026-03-12

Dimethicone

Common Name(s): Pdms,polydimethylsiloxane,silicone fluid

CAS Number: 9006-65-9

DESCRIPTION

What It Does: Provides silicone-characteristic silky feel and skin protection with adjustable viscosity.

Why It's Used: The benchmark cosmetic silicone โ€“ sets the gold standard for silky application feel, spreadability, and skin protection in virtually all skin care categories.

How It Works: Polydimethylsiloxane chain flexibility provides extremely low surface tension and high spreadability. inert si-o backbone provides chemical stability and excellent skin tolerance. occlusive film formation reduces tewl. higher viscosity grades provide more intense conditioning.

Typically Found In: Moisturizers,foundations,primers,sunscreens โ€“ nearly universal

TECHNICAL DETAILS

Primary Category: Functional ingredient โ€“ polydimethylsiloxane

Secondary Functions: Barrier sealing,softening

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.1%โ€“30%

SOURCING & ETHICS

Vegan Status: Yes โ€“ synthetic

Halal Status: Yes

Source Notes: Plant-derived, synthetic or animal-derived. verify source.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 โ€“ very low

Comedogenicity Rating: 1/5 โ€“ low; formulation-dependent

Sensitivity Concerns: Non-irritating.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Excellent safety profile. ewg score: 1.

Works Well With: Humectants,ceramides,actives as carrier

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Dimethicone's exceptional silky feel arises from its very low intermolecular attractive forces (weak van der waals forces due to non-polar methyl groups) that allow silicone chains to slide freely over skin. the coefficient of kinetic friction for pdms against skin (~0.04) is among the lowest of any cosmetic material โ€“ explaining why even small amounts transform product feel.

Last Verified: Cosing database,cir safety assessment

Primary Sources: 2026-03-12

Glycerin

Common Name(s): Glycerol,glycerine,1,2,3-propanetriol

CAS Number: 56-81-5

DESCRIPTION

What It Does: Glycerin pulls water from the environment and deeper skin layers into the outer skin layer (epidermis), boosting moisture levels and keeping skin soft, smooth, and plump.

Why It's Used: It is used in virtually every moisturizer, serum, and cleanser because it is highly effective at hydrating skin, is well-tolerated by all skin types, and enhances the texture and spreadability of formulations.

How It Works: As a humectant, glycerin forms hydrogen bonds with water molecules, trapping them in the skin. it also reinforces the skin barrier by integrating into lipid structures between skin cells.

Typically Found In: Moisturizers,serums,cleansers,toners,sheet masks,sunscreens,body lotions,shampoos,conditioners

TECHNICAL DETAILS

Primary Category: Humectant

Secondary Functions: Skin barrier support,emollient,solvent

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 1%โ€“30% (typical: 3โ€“10%)

SOURCING & ETHICS

Vegan Status: Yes โ€“ plant-derived (coconut, soy, palm) or synthetic

Halal Status: Yes โ€“ when plant-derived or synthetic; verify source with supplier

Source Notes: Derived from plant oils via hydrolysis or saponification; synthetic versions also available. palm-derived glycerin carries sustainability concerns.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 โ€“ very low; non-irritating at all standard concentrations

Comedogenicity Rating: 0/5 โ€“ non-comedogenic

Sensitivity Concerns: Extremely rare allergic reactions; generally safe for all skin types including sensitive and baby skin

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Widely recognized as safe. ewg hazard score: 1. no significant concerns for irritation, sensitization, or toxicity at typical concentrations (up to 50%).

Works Well With: Hyaluronic acid,ceramides,niacinamide,panthenol,urea,peptides,retinol,ahas/bhas

Avoid Combining With: No known incompatibilities at standard concentrations

SCIENTIFIC NOTE

Glycerin is an endogenous skin component found naturally in the stratum corneum. aquaporin-3 channels in keratinocytes facilitate glycerin transport, making it integral to natural skin hydration pathways.

Last Verified: Cosing database,cir safety assessment,ewg skin deep,inci decoder

Primary Sources: 2026-03-12