Round Lab Birch Juice Moisturizing Toner (300 ml) | Korean Skin Care

DESCRIPTION

What It Does: Ascorbic acid neutralizes free radicals, stimulates collagen production, inhibits melanin synthesis for a brighter complexion, and supports skin repair.

Why It's Used: It is used because it offers comprehensive antioxidant and brightening benefits supported by extensive clinical evidence. it is the most bioavailable form of vitamin c for topical application.

How It Works: As an antioxidant, it donates electrons to neutralize reactive oxygen species. it is an essential cofactor for the hydroxylation of proline and lysine in collagen synthesis. it inhibits tyrosinase, the enzyme responsible for melanin production, reducing hyperpigmentation.

Typically Found In: Vitamin c serums,brightening moisturizers,antioxidant formulations,spf products,eye creams

TECHNICAL DETAILS

Primary Category: Active ingredient – vitamin c

Secondary Functions: Collagen booster,tyrosinase inhibitor,ph adjuster

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 5%–20% (effective range: 10–20%; ph must be below 3.5 for activity)

SOURCING & ETHICS

Vegan Status: Yes – synthetically produced or corn/plant-derived

Halal Status: Yes

Source Notes: Commercially produced by reichstein synthesis or guangxi fermentation process from glucose. some plant-derived versions exist.

SKIN COMPATIBILITY

Irritancy Rating: 2/5 – low to moderate; low ph formulations can cause initial tingling or stinging, especially at concentrations above 15%

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Acidic ph can irritate sensitive or compromised skin barriers. highly unstable – oxidizes rapidly when exposed to air, light, and heat (turns orange/brown). use in the morning under spf.

Safe for Sensitive Skin: Use with caution – start at lower concentrations (5–10%). stabilized derivative forms (vitamin c derivatives) may be better tolerated.

SAFETY & COMPATIBILITY

Safety Profile: Very safe; well-studied. key concern is formulation stability, not safety. ewg hazard score: 1.

Works Well With: Vitamin e (tocopherol) – synergistic antioxidant effect,ferulic acid – stabilizing and boosting,spf,hyaluronic acid,niacinamide (use at different times if concentrations are high)

Avoid Combining With: Retinol (use at separate times – ph incompatibility),benzoyl peroxide (oxidizes vitamin c),ahas/bhas (cumulative irritation risk)

SCIENTIFIC NOTE

L-ascorbic acid is the only form of vitamin c that is proven bioactive in skin at the molecular level. its instability (rapid oxidation) has driven development of numerous stable derivatives including ascorbyl glucoside, magnesium ascorbyl phosphate, and ascorbyl tetraisopalmitate.

Last Verified: Cosing database,cir safety assessment,pinnell et al. studies,journal of the american academy of dermatology

Primary Sources: 2026-03-12

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 – 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%–10%

SOURCING & ETHICS

Vegan Status: Yes – synthetic

Halal Status: Yes

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

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – 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

DESCRIPTION

What It Does: Provides transparent gel textures and thickening at very low concentrations via ph-responsive swelling.

Why It's Used: The most widely used gel thickener – provides crystal-clear, stable gels at concentrations as low as 0.1-0.5% with ph-controlled viscosity.

How It Works: Highly crosslinked polyacrylic acid remains tightly coiled at acidic ph. neutralization with naoh or triethanolamine ionizes carboxylic groups causing electrostatic repulsion that unfolds and swells the polymer coils, dramatically increasing viscosity. concentration-dependent thickening.

Typically Found In: Gels,serums,emulsions,sunscreens

TECHNICAL DETAILS

Primary Category: Functional ingredient – polyacrylic acid thickener

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.1%–2%

SOURCING & ETHICS

Vegan Status: Yes – synthetic

Halal Status: Yes

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Good safety profile at recommended concentrations. ewg score: 1–2.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Carbomer's ph-responsive swelling mechanism provides an elegant formulation control tool: a neutralized gel can be liquefied by ph reduction (adding acid) and re-thickened by reneutralization. this reversible rheology control allows two-phase products that mix on application without the need for mechanical emulsification.

Last Verified: Cosing database,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides antioxidant protection, soothing anti-inflammatory effects, and skin-conditioning benefits through plant-derived polyphenols and phytochemicals.

Why It's Used: Plant extracts concentrate bioactive phytochemicals evolved for environmental protection — uv, microbial, and oxidative stressors — that translate to skin benefits.

How It Works: Polyphenols (flavonoids, phenolic acids) inhibit nf-κb-mediated inflammatory signaling, scavenge reactive oxygen species through electron donation, and chelate pro-oxidant metal ions to reduce oxidative skin damage.

Typically Found In: Serums,toners,moisturizers,masks,essences

TECHNICAL DETAILS

Primary Category: Botanical extracts

Secondary Functions: Antioxidant,anti-inflammatory

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.1–10%

SOURCING & ETHICS

Vegan Status: Yes

Halal Status: Yes

Source Notes: Plant-derived extract; no animal components.

SKIN COMPATIBILITY

Irritancy Rating: 1

Comedogenicity Rating: 0

Sensitivity Concerns: Low sensitization potential at recommended use concentrations.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

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

Works Well With: Niacinamide,hyaluronic acid,vitamin c,ceramides

Avoid Combining With: Strong oxidizing agents

SCIENTIFIC NOTE

Plant secondary metabolites (flavonoids, terpenes, phenolic acids) are biosynthesized as defense compounds against uv, herbivores, and pathogens. their anti-inflammatory activity typically derives from competitive inhibition of cox-2 and 5-lox enzymes (ic50 1–50 µm), while antioxidant activity involves single electron transfer (set) and hydrogen atom transfer (hat) mechanisms with structure-dependent rate constants.

Last Verified: Cosing eu database; pcpc cosmetic ingredient safety reviews; phytochemical and ethnobotanical literature

Primary Sources: 2025-01-15

DESCRIPTION

What It Does: Provides glycyrrhizic acid anti-inflammatory and cortisol-potentiating soothing activity.

Why It's Used: The anti-inflammatory licorice active — dipotassium glycyrrhizate provides stronger anti-inflammatory activity than glabridin-containing licorice extract, making it the preferred licorice active for anti-inflammatory formulations.

How It Works: Glycyrrhizic acid inhibits 11-beta-hsd (11-beta-hydroxysteroid dehydrogenase) which inactivates cortisol to cortisone. local cortisol levels increase providing anti-inflammatory activity analogous to mild topical corticosteroid. also inhibits phospholipase a2 and prostaglandin synthesis directly.

Typically Found In: Sensitive skin serums,anti-inflammatory products,anti-itch formulas

TECHNICAL DETAILS

Primary Category: Active ingredient – anti-inflammatory licorice

Secondary Functions: Redness reduction,anti-inflammatory,calming

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.1%–1%

SOURCING & ETHICS

Vegan Status: Yes – from glycyrrhiza glabra root

Halal Status: Yes

Source Notes: Plant-derived extract or synthetic.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Non-irritating; ideal for reactive and sensitive skin.

Safe for Sensitive Skin: Yes – particularly recommended for sensitive skin

SAFETY & COMPATIBILITY

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

Works Well With: Ceramides,panthenol,allantoin,hyaluronic acid,centella asiatica

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Dipotassium glycyrrhizate's 11-beta-hsd inhibition provides a corticosteroid-potentiating mechanism: by preventing cortisol deactivation to cortisone, it effectively amplifies the anti-inflammatory activity of the skin's own naturally produced glucocorticoid without introducing exogenous steroids — providing a 'natural steroid potentiation' that explains why licorice preparations have been used as a topical anti-inflammatory for millennia.

Last Verified: Cosing database,armanini et al. glycyrrhizate review

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides metal ion chelation to prevent product degradation and boost preservative and antioxidant efficacy.

Why It's Used: The most essential stability ingredient in cosmetics — disodium edta's metal chelation prevents rancidity, discoloration, and preservative failure caused by trace metal contamination in virtually all aqueous cosmetic formulations.

How It Works: Ethylenediaminetetraacetic acid provides six potential coordination sites for metal ions (aminodiacetate groups). chelates ca²⁺, mg²⁺ (stability), fe³⁺ (fenton radical prevention), cu²⁺ (oxidase inhibition). disrupts gram-negative bacterial outer membrane by chelating membrane calcium, enhancing preservative penetration.

Typically Found In: Virtually all aqueous cosmetics — creams, lotions, shampoos, toners

TECHNICAL DETAILS

Primary Category: Functional ingredient – chelating agent

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.005%–0.1%

SOURCING & ETHICS

Vegan Status: Yes – synthetic

Halal Status: Yes

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Good safety profile at recommended concentrations. ewg score: 1–2.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Disodium edta's preservative potentiation against gram-negative bacteria is mechanistically elegant: gram-negative outer membranes contain lipopolysaccharide stabilised by calcium and magnesium bridges. edta chelates these metal ions, destabilising the lps layer and creating pores that allow hydrophobic preservatives (phenoxyethanol, parabens) to penetrate — converting gram-negative-resistant preservatives into broad-spectrum ones.

Last Verified: Cosing database,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Delivers characteristic cosmetic function at recommended use concentration.

Why It's Used: Selected for functional contribution and formulation compatibility supported by cosmetic science and regulatory safety data.

How It Works: Works through the mechanism of its molecular class — physicochemical or biological interaction with skin proteins, lipids, or receptors as documented in peer-reviewed cosmetic literature.

Typically Found In: Skin care formulations

TECHNICAL DETAILS

Primary Category: Active ingredient – cosmetic active

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.1%–10%

SOURCING & ETHICS

Vegan Status: Conditional

Halal Status: Yes

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Good safety profile at recommended concentrations. ewg score: 1–2.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Glycereth-26 has an established safety and efficacy profile within the cosmetic regulatory framework at standard use concentrations.

Last Verified: Cosing database,glycereth-26 technical literature

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides natural origin antimicrobial preservation alongside skin conditioning in clean beauty formulations.

Why It's Used: Natural-origin preservative for truly natural formulations seeking effective preservation without synthetic preservatives.

How It Works: Monoglyceride structure inserts into microbial cell membranes via the caprylic acid chain, disrupting membrane integrity. glycerol moiety contributes skin conditioning. effective against gram-positive bacteria and some yeasts at formulation concentrations.

Typically Found In: Natural and organic cosmetics,clean beauty,cosmos-certified products

TECHNICAL DETAILS

Primary Category: Functional ingredient – natural monoglyceride preservative

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.3%–1.5%

SOURCING & ETHICS

Vegan Status: Yes – from glycerol and caprylic acid (plant sources)

Halal Status: Yes

Source Notes: From vegetable glycerol and plant-derived caprylic acid (coconut/palm kernel). cosmos-approved for certified natural cosmetics.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Good safety profile at recommended concentrations. ewg score: 1–2.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Glyceryl caprylate's preservation mechanism (membrane disruption via monoglyceride structure) is distinct from synthetic preservatives (protein enzyme inhibition). this mechanistic difference is why it is approved in cosmos natural certification where synthetic enzyme inhibitors are not permitted.

Last Verified: Cosing database,cosmos standard,basf technical data

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Delivers characteristic cosmetic function — skin conditioning, antioxidant protection, active biological benefit, or formulation function — at recommended use concentration.

Why It's Used: Selected for functional contribution and formulation compatibility supported by cosmetic science and regulatory safety data.

How It Works: Works through the mechanism of its molecular class — physicochemical or biological interaction with skin proteins, lipids, or receptors as documented in peer-reviewed cosmetic literature.

Typically Found In: Skin care formulations

TECHNICAL DETAILS

Primary Category: Active ingredient – cosmetic active

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.1%–10%

SOURCING & ETHICS

Vegan Status: Conditional

Halal Status: Yes

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Good safety profile at recommended concentrations. ewg score: 1–2.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Glyceryl glucoside has an established safety and efficacy profile within the cosmetic regulatory framework at standard use concentrations.

Last Verified: Cosing database,glyceryl glucoside technical literature

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides nmf amino acid skin conditioning and collagen-constituent support.

Why It's Used: The collagen amino acid — glycine is the most abundant amino acid in collagen (every third residue in the triple helix is glycine) making topical glycine the most physiologically relevant collagen-support amino acid.

How It Works: Nmf component via zwitterionic water retention. collagen triple helix requires gly-x-y repeat where glycine's small size allows close packing. wound healing via fibroblast glutathione synthesis support. anti-inflammatory via glycine-gated chloride channel activation (inhibitory neuromodulator).

Typically Found In: Skin conditioning products,wound healing,nmf moisturisers

TECHNICAL DETAILS

Primary Category: Active ingredient – simplest amino acid

Secondary Functions: Skin conditioning

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.5%–5%

SOURCING & ETHICS

Vegan Status: Yes – fermentation or synthetic

Halal Status: Yes

Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Well-tolerated by most skin types.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Good safety profile at recommended concentrations. ewg score: 1–2.

Works Well With: Standard skincare actives

Avoid Combining With: No known significant incompatibilities

SCIENTIFIC NOTE

Glycine's mandatory presence at every third position in collagen's triple helix (gly-x-y repeat) arises from its unique zero side-chain structure — only glycine is small enough to fit at the sterically restricted centre of the triple helix where the three polypeptide chains cross. no other amino acid can substitute for glycine in the collagen triple helix without disrupting the structure, making glycine irreplaceable in collagen biology.

Last Verified: Cosing database,cir safety assessment

Primary Sources: 2026-03-12