Guava Vitamin C Dark Spot Serum

DESCRIPTION

What It Does: Provides stable vitamin c activity combining formulation stability with good skin delivery.

Why It's Used: Best balance of stability and bioavailability among vitamin c derivatives — 3-o-ea provides stability superior to ascorbic acid with better bioavailability than large ester forms like ascorbyl tetraisopalmitate.

How It Works: C3 ether position protection prevents oxidation at the most vulnerable c2-c3 enediol. more lipophilic than ascorbic acid for improved skin penetration. ether bond resistant to hydrolysis in formulation but cleaved by skin esterases for active ascorbic acid release in viable epidermis.

Typically Found In: Stable brightening serums,anti-aging vitamin c products

TECHNICAL DETAILS

Primary Category: Active ingredient – ethyl ascorbic acid

Secondary Functions: Tyrosinase inhibitor,collagen cofactor

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 1%–3%

SOURCING & ETHICS

Vegan Status: Yes – synthetic

Halal Status: Yes

Source Notes: Synthetically produced vitamin c derivative.

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: Tocopherol,ferulic acid,niacinamide,spf

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

3-o-ethyl ascorbic acid's ether bond at c3 provides fundamentally different stability vs ester-bonded vitamin c derivatives (ascorbyl palmitate, ascorbyl tetraisopalmitate). ether bonds are far more resistant to chemical hydrolysis than ester bonds — 3-o-ea is more hydrolysis-stable than c6 ester derivatives while still providing bioactive release via ether cleavage in skin.

Last Verified: Cosing database,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides stable gradual-release vitamin c activity for brightening and antioxidant protection.

Why It's Used: Most formulation-stable vitamin c derivative — ascorbyl glucoside remains stable in aqueous formulations where pure ascorbic acid oxidises within days, providing sustained vitamin c delivery over weeks of shelf life.

How It Works: Alpha-glucoside bond resists oxidation until cleaved by skin alpha-glucosidase enzymes. releases free l-ascorbic acid in viable epidermis. released ascorbic acid inhibits tyrosinase, stimulates collagen synthesis, and provides antioxidant activity. glucose group provides enhanced water solubility vs ascorbic acid.

Typically Found In: Stable vitamin c serums,brightening products,anti-aging

TECHNICAL DETAILS

Primary Category: Active ingredient – stable vitamin c glucoside

Secondary Functions: Tyrosinase inhibitor,collagen cofactor

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 1%–5%

SOURCING & ETHICS

Vegan Status: Yes – enzymatic synthesis from ascorbic acid and glucose

Halal Status: Yes

Source Notes: Synthetically produced vitamin c derivative.

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: Tocopherol,ferulic acid,niacinamide,spf

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Ascorbyl glucoside's stability advantage (18+ months in aqueous formulation vs days for ascorbic acid) arises from the glucose group's steric protection of ascorbic acid's c2 enediol that is the primary oxidation site. glucosidase cleavage in skin removes this protection in situ, releasing active ascorbic acid only where enzymatic activity exists — providing both formulation stability and bioactivation where needed.

Last Verified: Cosing database,yamamoto et al. ascorbyl glucoside stability study

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

C9-12 alkane has an established safety and efficacy profile within the cosmetic regulatory framework at standard use concentrations.

Last Verified: Cosing database,c9-12 alkane technical literature

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides stable vitamin c phosphate brightening with magnesium mineral skin conditioning.

Why It's Used: Gentle stable vitamin c for sensitive skin — map provides effective brightening without the irritation of pure ascorbic acid at equivalent brightening concentration.

How It Works: Phosphate ester protection vs oxidation. converted to ascorbic acid by phosphatase enzymes in skin. magnesium counterion provides mild anti-inflammatory skin benefit. inhibits tyrosinase for brightening. stimulates collagen synthesis.

Typically Found In: Brightening serums,sensitive skin vitamin c

TECHNICAL DETAILS

Primary Category: Active ingredient – magnesium vitamin c

Secondary Functions: Tyrosinase inhibitor,collagen cofactor

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 1%–5%

SOURCING & ETHICS

Vegan Status: Yes – synthetic

Halal Status: Yes

Source Notes: Synthetically produced vitamin c derivative.

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: Tocopherol,ferulic acid,niacinamide,spf

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Map's magnesium counterion provides a minor skin benefit beyond the vitamin c activity: mg²⁺ is an essential cofactor for 300+ enzymatic reactions in cells. as map hydrolyses releasing ascorbate and mg²⁺, the locally released magnesium may support keratinocyte enzymatic function, providing a supplementary skin benefit unique to magnesium vs sodium ascorbyl phosphate.

Last Verified: Cosing database,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides humectant and solvent functionality from sustainable corn-based fermentation.

Why It's Used: Bio-based propylene glycol alternative from renewable corn — propanediol provides equivalent functionality to propylene glycol with sustainable renewable feedstock and superior skin feel.

How It Works: Two oh groups provide humectant water binding. excellent solvent for fragrances, actives, and preservatives. mild antimicrobial from diol structure for preservative system boosting. renew corn fermentation origin (dupont zemea process). better skin feel than propylene glycol — less sticky.

Typically Found In: Virtually all cosmetic categories as pg alternative

TECHNICAL DETAILS

Primary Category: Functional ingredient – 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%–20%

SOURCING & ETHICS

Vegan Status: Yes – from corn sugar fermentation

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

Propanediol's dupont tate & lyle bio products 'zemea' process ferments corn sugar to 1,3-propanediol using engineered e. coli — one of the first commercially viable bio-fermentation routes to a cosmetic diol previously made only from petroleum. the renewable route produces chemically identical 1,3-propanediol while reducing carbon footprint by approximately 40% vs petrochemical synthesis.

Last Verified: Cosing database,dupont tate & lyle zemea technical data,cir safety assessment

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides antioxidant protection from reactive oxygen species, reduces inflammatory cytokine production in skin, and conditions skin through the plant's phytochemical complex.

Why It's Used: Natural origin narrative, traditional use heritage, and multi-functional phytochemical profile supporting concurrent skin care claims from one ingredient.

How It Works: Polyphenols, terpenoids, and alkaloids scavenge ros via h• donation, inhibit nf-kb or cox-2 inflammatory pathways, and interact with skin surface proteins for conditioning.

Typically Found In: Botanical skin care,natural products

TECHNICAL DETAILS

Primary Category: Active ingredient – antioxidant

Secondary Functions: Free radical scavenging,anti-aging

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: Plant-derived extract or synthetic.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Non-irritating; well-tolerated.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

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

Works Well With: Vitamin c,vitamin e,ferulic acid,spf,other antioxidants

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Plant secondary metabolites evolved as photoprotectants and antimicrobials — mechanisms directly applicable to cosmetic antioxidant and anti-inflammatory activity in human skin.

Last Verified: Cosing database,psidium guajava fruit extract botanical review

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides stable water-soluble vitamin c with documented anti-acne activity beyond typical brightening benefits.

Why It's Used: The anti-acne vitamin c derivative — sap's documented anti-p. acnes activity makes it uniquely suited for acne-brightening formulations targeting both acne and post-acne hyperpigmentation simultaneously.

How It Works: Phosphate ester resists oxidation in aqueous formulation. converted to ascorbic acid by alkaline phosphatase in viable epidermis. anti-acne via reduction of p. acnes oxidative stress and direct antimicrobial activity. tyrosinase inhibition for brightening.

Typically Found In: Anti-acne brightening serums,oily skin products

TECHNICAL DETAILS

Primary Category: Active ingredient – phosphate vitamin c

Secondary Functions: Tyrosinase inhibitor,collagen cofactor

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 1%–5%

SOURCING & ETHICS

Vegan Status: Yes – synthetic

Halal Status: Yes

Source Notes: Synthetically produced vitamin c derivative.

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: Tocopherol,ferulic acid,niacinamide,spf

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Sodium ascorbyl phosphate's anti-p. acnes activity was demonstrated by klock et al. (2005) showing sap at 1% reduced p. acnes populations and reduced inflammatory acne lesions in a clinical study. the mechanism involves ascorbic acid's pro-oxidant activity in p. acnes — generating reactive oxygen species toxic to the bacterium, which is the opposite of ascorbic acid's antioxidant role in human cells.

Last Verified: Cosing database,klock et al. sap anti-acne study

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides gentle, effective cleansing with minimal skin irritation — suitable for sensitive skin, baby care, and facial cleansers requiring mild surfactant systems.

Why It's Used: Amino acid and organic acid surfactants provide the gentlest anionic cleansing — glutamate, taurate, and sarcosinate head groups have inherently lower skin protein denaturing activity than sulfate head groups from the amino acid's protein-complementarity chemistry.

How It Works: The amino acid-derived head group (glutamate, glycinate, taurate, sarcosinate) provides anionic character at cleansing ph while the amino acid backbone has structural complementarity with skin proteins — reducing the electrostatic protein-surfactant binding energy that causes irritation compared to simple sulfate anionics.

Typically Found In: Gentle cleansers,baby care,facial wash

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: 5%–25%

SOURCING & ETHICS

Vegan Status: Yes

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

Amino acid surfactant mildness ranking: cocoyl glutamate ≈ cocoyl glycinate > cocoyl sarcosinate > lauryl glucoside > sles > sls — the amino acid head group provides consistently lower zein protein solubilisation (irritation predictor) than equivalent-chain-length sulfates.

Last Verified: Cosing database,sodium polyacryloyldimethyl taurate amino acid surfactant review

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Delivers potent, stable vitamin c deep into skin for superior antioxidant protection and collagen stimulation.

Why It's Used: Premium anti-aging requiring proven deep penetration and exceptional stability in all formulation types.

How It Works: Four hexyl decyl chains provide lipophilicity for membrane penetration. progressive enzymatic hydrolysis releases ascorbic acid within deeper skin layers.

Typically Found In: Luxury vitamin c serums,anti-aging products,brightening formulations

TECHNICAL DETAILS

Primary Category: Active ingredient – vitamin c derivative

Secondary Functions: Superior penetration,stable vitamin c

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 0.5%–3%

SOURCING & ETHICS

Vegan Status: Yes – synthetic

Halal Status: Yes

Source Notes: Fully synthetic. produced by esterification of ascorbic acid with 2-hexyl decanol.

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: Tocopherol,ferulic acid,niacinamide,spf

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Clinical studies confirm thd reaches the dermis more effectively than l-ascorbic acid, stimulating fibroblast collagen production at the structural skin level.

Last Verified: Cosing database,shefer et al. penetration studies

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides brightening by inhibiting uv-induced plasminogen activation that triggers melanocyte stimulation.

Why It's Used: Novel brightening mechanism — tranexamic acid targets uv-induced melanocyte stimulation upstream of tyrosinase activity, providing complementary brightening to tyrosinase inhibitors with exceptional tolerability.

How It Works: Lysine analogue binds lysine-binding sites on plasminogen preventing its conversion to plasmin. uv-activated plasmin normally increases keratinocyte arachidonic acid release stimulating melanocyte activity via prostaglandin e2 and alpha-msh. txa blocks this uv-melanocyte signalling cascade upstream of pigment synthesis.

Typically Found In: Brightening serums,anti-melasma products,uv-induced pigmentation

TECHNICAL DETAILS

Primary Category: Active ingredient – lysine analogue brightening

Secondary Functions: Melanin inhibition,hyperpigmentation reduction

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 – synthetic

Halal Status: Yes

Source Notes: Synthetic or plant-derived.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Non-irritating; well-tolerated.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

Safety Profile: Excellent safety profile. use with spf for maximum efficacy. ewg score: 1.

Works Well With: Niacinamide,vitamin c,alpha-arbutin,tranexamic acid,spf

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Tranexamic acid's brightening mechanism was discovered serendipitously — it was originally a haemostasis drug for reducing surgical bleeding. dermatologists noted that patients receiving txa for bleeding showed improved melasma, leading to investigation that revealed the plasminogen–prostaglandin–melanocyte signalling cascade as a completely previously unknown brightening target.

Last Verified: Cosing database,huang et al. tranexamic acid brightening review

Primary Sources: 2026-03-12