HERSAY Dark Spot Corrector Serum

DESCRIPTION

What It Does: Soothes irritation, accelerates wound healing, promotes skin cell renewal, and provides mild keratolytic exfoliation.

Why It's Used: Gold standard multi-function soothing active – one of the most widely used cosmetic ingredients across all product types for its exceptional tolerability and clinically proven multi-action skin conditioning.

How It Works: Promotes keratinocyte proliferation and fibroblast migration for wound healing. mild keratolytic activity by disrupting corneocyte binding. anti-irritant via direct protein binding and anti-inflammatory cytokine reduction. humectant activity via hydroxyl groups.

Typically Found In: Post-procedure products,sensitive skin formulas,wound care,anti-acne treatments,baby products

TECHNICAL DETAILS

Primary Category: Active ingredient – soothing / anti-inflammatory

Secondary Functions: Wound healing,keratolytic,anti-irritant

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 or comfrey-derived

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: Exceptionally well-tolerated; suitable for all skin types including baby and compromised 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

Allantoin's keratinocyte proliferation stimulation occurs via receptor-mediated signaling (possibly machr activation) rather than non-specific irritation-driven proliferation, making it a true wound-healing stimulant rather than a pro-inflammatory proliferative signal.

Last Verified: Cosing database,cir safety assessment,araújo et al. allantoin review

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides potent tyrosinase inhibition with improved stability and tolerability over other arbutin forms.

Why It's Used: Premium arbutin — alpha configuration provides 10× greater tyrosinase inhibition than beta-arbutin at equivalent concentration, making alpha-arbutin the most effective arbutin form.

How It Works: Alpha-glucoside linkage provides enhanced metabolic stability vs beta-arbutin (less enzymatic hydrolysis to free hydroquinone in skin). inhibits tyrosinase via competitive substrate inhibition (ic50 ~24μg/ml vs beta-arbutin ~525μg/ml — 20× more potent). inhibits dopa oxidase step in melanogenesis.

Typically Found In: Brightening serums,anti-spot products,premium lightening

TECHNICAL DETAILS

Primary Category: Active ingredient – arbutin brightening agent

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%–2%

SOURCING & ETHICS

Vegan Status: Yes – synthetic enzymatic synthesis

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

Alpha-arbutin's 10–20× greater potency vs beta-arbutin at equivalent concentration arises from the alpha-glycosidic bond geometry — the alpha configuration positions the hydroquinone aglycone at a specific orientation relative to the glucose that fits the tyrosinase active site copper more precisely than the beta isomer's different spatial arrangement.

Last Verified: Cosing database,sugimoto et al. arbutin tyrosinase study

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides the specific b-vitamin's characteristic skin and hair benefits: brightening and barrier reinforcement (niacinamide), keratin structural support (biotin), deep conditioning humectancy (panthenol).

Why It's Used: B-vitamins operate through fundamental cellular biochemistry pathways — nad⁺ for niacinamide, carboxylase cofactor for biotin, coa synthesis for panthenol — providing multi-benefit activity from essential metabolic chemistry.

How It Works: Acts as coenzyme or substrate in essential metabolic pathways: niacinamide → nad⁺/nadp⁺ → ceramide synthesis, melanosome transfer inhibition; biotin → carboxylase → fatty acid synthesis for ceramide; panthenol → pantothenic acid → coa → lipid metabolism.

Typically Found In: Multi-function skin care,b-vitamin formulas

TECHNICAL DETAILS

Primary Category: Active ingredient – vitamin b complex

Secondary Functions: Antioxidant cofactor,metabolic support

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: Synthetically produced for cosmetic use.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: Non-irritating; excellent tolerability.

Safe for Sensitive Skin: Yes

SAFETY & COMPATIBILITY

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

Works Well With: Other b vitamins,niacinamide,antioxidant complexes

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

B-vitamins are water-soluble, non-irritating, and well-tolerated across all skin types — providing clinical efficacy with an exceptional safety profile from their essential nutrient status.

Last Verified: Cosing database,d-panthenol b-vitamin skin review

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides the gentlest chemical exfoliation with simultaneous antioxidant, moisture retention, and barrier support.

Why It's Used: Preferred exfoliant for rosacea, eczema, sensitive skin, and post-procedure recovery where standard ahas cause unacceptable irritation.

How It Works: Hydrolyzes slowly on skin surface to gluconic acid providing gentle exfoliation. multiple hydroxyl groups enable water binding (humectant) and metal chelation (antioxidant).

Typically Found In: Sensitive skin exfoliants,rosacea treatments,eczema care,post-procedure recovery

TECHNICAL DETAILS

Primary Category: Active ingredient – polyhydroxy acid (pha)

Secondary Functions: Gentle exfoliation,antioxidant,humectant

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 5%–15%

SOURCING & ETHICS

Vegan Status: Yes – fermentation or synthetic

Halal Status: Yes

Source Notes: Fermentation-derived from glucose or synthetic. among the safest chemical exfoliants available.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: No photosensitization; no stinging; suitable for very sensitive skin.

Safe for Sensitive Skin: Yes – ideal for sensitive, reactive, rosacea, and eczema-prone skin; no photosensitization

SAFETY & COMPATIBILITY

Safety Profile: Exceptional safety profile. no photosensitization. ewg score: 1.

Works Well With: Ceramides,niacinamide,hyaluronic acid,soothing actives

Avoid Combining With: No significant incompatibilities

SCIENTIFIC NOTE

Phas have molecular weights 2–3× larger than ahas, limiting penetration to superficial layers. combined humectant and antioxidant properties make them uniquely well-tolerated while providing meaningful exfoliation.

Last Verified: Cosing database,green & yu (2003) pha review,cir safety assessment

Primary Sources: 2026-03-12

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%–30% (typical: 3–10%)

SOURCING & ETHICS

Vegan Status: Yes – plant-derived (coconut, soy, palm) or synthetic

Halal Status: Yes – 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 – very low; non-irritating at all standard concentrations

Comedogenicity Rating: 0/5 – 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

DESCRIPTION

What It Does: Niacinamide strengthens the skin barrier, reduces visible pore size, regulates sebum production, fades dark spots, and improves skin texture and tone.

Why It's Used: It is used because it addresses multiple skin concerns at once without irritation, making it suitable for all skin types. it is stable in formulations and pairs well with most other actives.

How It Works: Niacinamide inhibits the transfer of melanosomes (pigment packets) to skin cells, reducing hyperpigmentation. it also stimulates ceramide synthesis to strengthen the skin barrier and reduces inflammation by modulating cytokine activity.

Typically Found In: Serums,moisturizers,toners,cleansers,eye creams,sunscreens,primers

TECHNICAL DETAILS

Primary Category: Active ingredient – vitamin

Secondary Functions: Barrier repair,brightening,anti-inflammatory

Application Areas:

Facial Skincare

Body Care

Hair Care

Beard Care

Color Cosmetics (Makeup)

Dietary/Oral Supplements

Typical Concentration Range: 2%–10% (typical: 5%; higher concentrations may cause flushing in some individuals)

SOURCING & ETHICS

Vegan Status: Yes – synthetically produced

Halal Status: Yes – synthetic origin

Source Notes: Commercially produced via synthesis from nicotinic acid or 3-cyanopyridine. no animal-derived sources used in cosmetic-grade niacinamide.

SKIN COMPATIBILITY

Irritancy Rating: 1/5 – very low; concentrations above 10% may cause temporary flushing in sensitive individuals

Comedogenicity Rating: 0/5 – non-comedogenic

Sensitivity Concerns: At concentrations >10%, some users experience niacin flush (transient redness/tingling). generally very well-tolerated.

Safe for Sensitive Skin: Yes – one of the best-tolerated actives for sensitive skin

SAFETY & COMPATIBILITY

Safety Profile: Extensively studied and considered very safe. ewg hazard score: 1. no significant systemic toxicity concerns at topical concentrations.

Works Well With: Retinol,peptides,ahas/bhas,hyaluronic acid,ceramides,zinc,vitamin c,spf

Avoid Combining With: High concentrations of vitamin c (ascorbic acid) may theoretically convert to niacin – use at different times if using pure l-ascorbic acid above 15%

SCIENTIFIC NOTE

Niacinamide is a precursor to nad+ and nadp+, coenzymes vital to cellular energy metabolism. its benefits for dna repair and mitochondrial function make it a key ingredient in anti-aging strategies.

Last Verified: Cosing database,cir safety assessment,ewg skin deep,pubmed clinical studies

Primary Sources: 2026-03-12

DESCRIPTION

What It Does: Provides the characteristic cosmetic function of its ingredient class through molecular chemistry at recommended use concentration.

Why It's Used: Tetrahydropiperine is selected for the specific functional properties of its molecular class — the chemical architecture of tetrahydropiperine delivers the required cosmetic performance through documented interactions with skin biology and formulation matrix.

How It Works: Functional groups interact with formulation and skin through h-bonding, ionic association, or receptor activity as appropriate.

Typically Found In: Cosmetic 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

Safety documented in cosing at standard formulation concentrations.

Last Verified: Cosing database,tetrahydropiperine technical review

Primary Sources: 2026-03-22