Are there usage precautions?

미백 및 항상화 효과 멜라닌 생성 억제 기미와 잡티 감소 효과 각질 제거 효과 Kojic acid is a cosmetic ingredient used for its skin-lightening and depigmenting effects, working by inhibiting the enzyme tyrosinase, which is crucial for melanin production. Also provides antioxidant benefits for enhanced skin radiance. (추천 피부타입: 민감성 피부 제외 모든 피부 타입)

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Ingredient Dictionary

KOJIC ACID

Kojic acid is a pyranone that is 4H-pyran substituted by a hydroxy group at position 5, a hydroxymethyl group at position 2 and an oxo group at position 4.

Clinical evidence

Dark spots B+

Amount studies used: 1%
When: evening
Irritation: moderate — start every other day

Grades were set by reading this ingredient’s studies. They describe the ingredient, not every product that contains it.

KOJIC ACID Molecular structure — Molecular structure

How much products actually contain

15 products state the amountmedian 0.01%0% at or above the amount studies used (1%)

under 0.01% 5
0.01–0.1% 5
0.1–1% 5
1% or more 0

Amounts are mostly stated by products named after the ingredient, so they may lean towards token amounts.

Of the products containing it, 19 list it before the 1% line and 47 after it (usually 1% or less).

Where no amount is stated, a product listing it early reaches the study amount about 37% of the time, one listing it late about 2%.

Clinical evidence grade by skin concern

B: one or two randomised trials

Has the most allergy reports among brightening ingredients.

1 references

Chang 2023, topical melasma treatments, meta-analysis of 45 studies / 2,359 people

Products using this ingredient

12 of 66 confirmed · likeliest to carry enough first · See all 66

Definition

Kojic Acid is the heterocyclic compound that conforms to the formula

Kojic acid is a pyranone that is 4H-pyran substituted by a hydroxy group at position 5, a hydroxymethyl group at position 2 and an oxo group at position 4. It has been isolated from the fungus Aspergillus oryzae. It has a role as an EC 1.14.18.1 (tyrosinase) inhibitor, a NF-kappaB inhibitor, an Aspergillus metabolite, a skin lightening agent, an EC 1.10.3.1 (catechol oxidase) inhibitor, an EC 1.10.3.2 (laccase) inhibitor, an EC 1.13.11.24 (quercetin 2,3-dioxygenase) inhibitor and an EC 1.4.3.3 (D-amino-acid oxidase) inhibitor. It is a member of 4-pyranones, a primary alcohol and an enol. It derives from a hydride of a 4H-pyran.

Source: PubChem

US FDA substance register · UNII 6K23F1TT52 · registered name KOJIC ACID · single chemical substance

Source: US FDA Unique Ingredient Identifier (UNII)

Cosmetic roles

Slows spoilage by oxygenANTIOXIDANTLightens hair or skinBLEACHING

Safety & regulatory references

Restricted: ASEAN · United Kingdom

Source: ASEAN Cosmetic Directive · EU Cosmetics Regulation · MFDS (Korea) cosmetic regulatory information · Taiwan FDA cosmetic ingredients · Taiwan FDA cosmetic regulations · UK cosmetics regulations (OPSS)

Taiwan

Maximum concentration : 2%

European Union

Product Type, body parts : Face and hand products
Maximum concentration in ready for use preparation : 1%

Source: MFDS (Korea) cosmetic regulatory information

Not classified under Korea’s toxic-substance GHS list · existing chemical substance

Source: Korea toxic substances GHS register (NIER)

EU Cosmetics Regulation, Annex III (restricted substances), entry 375 · maximum concentration 1 % · applies to Face and hand products

Source: EU restricted substances (Annex III)

Restriction III / 375 · SCCS opinion: Opinion on Kojic acid; Opinion on Kojic Acid

Source: EU CosIng ingredient list

Reviewed by CIR: Final Report of the Safety Assessment of Kojic Acid as Used in Cosmetics

Source: US Cosmetic Ingredient Review (CIR)

CIR reviewed this ingredient and flagged its status as: Insufficient Data Announcement: Amended Safety Assessment of Kojic Acid Used in Cosmetics (insufficient data or use not supported — CIR's own classification, not a full safety-as-used conclusion).

Source: US Cosmetic Ingredient Review (CIR)

More data — names, identifiers, properties, test records, literature

Official labels & definitions

JCIA labelling name コウジ酸: 本品は、次の化学式で表される複素環式化合物である。

Source: JCIA labelling names (Japan)

Names & identifiers

KOJIC ACIDINCI코직애씨드Korean label name (MFDS standard)コウジ酸Japanese labelling name

CAS No.chemical registry number: 501-30-4
EC No.EU chemical inventory number: 207-922-4
DTXSIDUS EPA chemical ID: DTXSID2040236
DTXCIDUS EPA compound ID: DTXCID0020236

IUPAC: 5-Hydroxy-2-(hydroxymethyl)-4H-pyran-4-one
Molecular formula: C6H6O4
Molecular weight: 142.11 g/mol

Measured properties

Appearance: Solid · Prismatic needles from acetone, ethanol+ether or methanol+ethyl acetate
Melting point: 153.5 °C · 161 °C
Solubility: Soluble in ethanol, ethyl ether, acetone, DMSO, slightly soluble in benzene · Soluble in water, acetone, slightly solluble in ether, insoluble in benzene
Dissociation constant: pKa = 7.66 (approx., at 25 °C)
Colour: colourless
Melting/freezing point: 153.5 ℃
Initial boiling point and range: 401.7 ℃
Flash point: 179.9 ℃
Vapour pressure: 0.00000321 ㎜Hg (25C)
Water solubility: 935000 ㎎/ℓ (25C)
Relative density: 1.542
n-Octanol/water partition coefficient (Kow): -0.64
Molecular weight: 142.11

Values measured on the substance itself. The KOSHA data are a reference for writing and reviewing safety data sheets, not a specification for a commercial raw material.

Source: PubChem · KOSHA safety data sheets (Korea)

What products actually use it for

What the 2 products reported to the US EPA with this ingredient use it for. Products outside cosmetics are included, so the top few rows are its main uses.

Antioxidant2

Source: US EPA CompTox dashboard