
Highlights
WHAT IS IT?
Serum with 3% Hyaluronic Acid
FEATURES
Highly concentrated with 3% Hyaluronic Acid, lightweight fluid texture, deeply moisturises skin, boosts skin's moisture levels in one use, hydrates and plumps skin, soothes and strengthens skin's moisture barrier, reduces appearance of fine lines and wrinkles, clinically proven for sensitive skin, suitable for very dry and dehydrated skin, prevents makeup crackling and clinging to dry patches
BEST FOR
dry
CHECKS
Does not contain known allergens or irritants as per description (implied by clinically proven for sensitive skin and preservative-free and cruelty-free claims)
Who Is It For?
Adults All Genders (not Specifically Mentioned Age Or Gender Assume General Adult Usage)What Does It Help With?
Dryness Dehydration Fine Lines Sensitive Skin Care Strengthening Moisture BarrierBudget
Mid-range ($30-$75)How To Use
Which routine should it be used in?
Instructions:
Key Information
What COSRX Says
Product Description:
The Cosrx Hyaluronic Acid 3 Serum is a highly concentrated formula infused with 3% Hyaluronic Acid to deeply moisturise skin. It has a lightweight fluid texture that penetrates the skin quickly and boosts skin's internal and external moisture levels with just one use! Hyaluronic Acid hydrates, plumps, soothes and strengthens the skin's natural moisture barrier for a healthy glow. It also fills in the skin to reduce the appearance of fine lines and wrinkles. The serum is clinically proven to suit sensitive skin. It is also ideal for very dry, dehydrated skin that easily loses moisture. For makeup users, it prevents makeup from cracking or clinging to dry patches. It is perfect for those looking for a high-efficacy serum that locks-in moisture and prevents further dehydration.
About the Brand:
Ingredients Overview
Ingredients List
Water, Butylene Glycol, Propanediol, Sodium Hyaluronate, Pentylene Glycol, Glycerin, Glyceryl Acrylate/Acrylic Acid Copolymer, Betaine, Sodium PCA, Sodium Lactate, PCA, Serine, Alanine, Glycine, Dimethicone, Butylene Glycol, Hydrogenated Lecithin, Sodium Methyl Stearoyl Taurate, Diethoxyethyl Succinate, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Sorbitan Isostearate, Tocopherol, Ceramide NP, Glycerin, Citric Acid
Key Ingredients
hyaluronic-acid
Ingredients Details
Alanine
Common Name(s): L-alanine,2-aminopropanoic acid
CAS Number: 56-41-7
DESCRIPTION
What It Does: Provides nmf-type humectant moisture retention and skin conditioning.
Why It's Used: Simple, well-tolerated nmf amino acid humectant for skin conditioning formulations.
How It Works: Small methyl side chain contributes to protein hydrophobic core but as free amino acid provides direct humectant activity via amino and carboxyl groups. converted to pyruvate for cellular atp production via gluconeogenesis.
Typically Found In: Nmf moisturizers,skin conditioning products
TECHNICAL DETAILS
Primary Category: Active ingredient โ amino acid
Secondary Functions: Nmf component,cellular energy
Application Areas:
Facial Skincare
Body Care
Hair Care
Beard Care
Color Cosmetics (Makeup)
Dietary/Oral Supplements
Typical Concentration Range: 0.5%โ5%
SOURCING & ETHICS
Vegan Status: Yes โ plant-derived or synthetic
Halal Status: Yes
Source Notes: Fermentation-derived or synthetic. natural skin component.
SKIN COMPATIBILITY
Irritancy Rating: 1/5 โ very low
Comedogenicity Rating: 0/5 โ non-comedogenic
Sensitivity Concerns: Non-irritating; endogenous skin molecule.
Safe for Sensitive Skin: Yes
SAFETY & COMPATIBILITY
Safety Profile: Excellent safety profile. natural skin nmf component. ewg score: 1.
Works Well With: Hyaluronic acid,ceramides,peptides,other amino acids
Avoid Combining With: No significant incompatibilities
SCIENTIFIC NOTE
Free alanine is among the most abundant amino acids in the stratum corneum nmf, where it contributes to the aqueous phase hydration that keeps the stratum corneum flexible and functional.
Last Verified: Cosing database,cir safety assessment
Primary Sources: 2026-03-12
Betaine
Common Name(s): Trimethylglycine,tmg,natural betaine
CAS Number: 107-43-7
DESCRIPTION
What It Does: Provides osmoprotective humectant conditioning with anti-irritant and mild foam-boosting activity.
Why It's Used: Natural-origin multifunctional osmolyte from sugar beet providing hydration, anti-irritancy, and conditioning in virtually every cosmetic category.
How It Works: Quaternary ammonium betaine provides zwitterionic character for water binding via ionic hydration. osmoprotective function at 100โ500mm as compatible solute protecting cells from osmotic stress. reduces surfactant irritation by competing with sls for protein binding sites. mild foam enhancement.
Typically Found In: Virtually all categories โ moisturisers, shampoos, cleansers
TECHNICAL DETAILS
Primary Category: Functional ingredient โ 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: 0.5%โ10%
SOURCING & ETHICS
Vegan Status: Yes โ from beta vulgaris (sugar beet) molasses
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
Betaine's anti-irritant mechanism for surfactant systems involves competitive protein protection: betaine at high concentrations preferentially interacts with skin proteins, occupying binding sites that would otherwise be occupied by surfactant molecules causing protein denaturation. this competition reduces available protein binding for irritating surfactants, explaining betaine's well-documented ability to reduce sls irritation when co-formulated.
Last Verified: Cosing database,craig betaine osmoprotective review,cir safety assessment
Primary Sources: 2026-03-12
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%โ10%
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
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%โ10%
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