Cosmetics · Quasi-drug actives
Kojic Acid
コウジ酸 (Kōji-san)
Also known as: 5-Hydroxy-2-(hydroxymethyl)-4H-pyran-4-one
Looking for a Japanese supplier of Kojic Acid? Tell usWhy now · 2022 — ongoing
Koji Beyond Sake: Industrial Applications Western Brands Are Discovering
Koji (Aspergillus oryzae) — Japan's national microorganism — is moving from sake/miso into plant-based meats, alternative charcuterie, and bakery applications worldwide.
Read the trend reportAt a glance
| Category | Cosmetics |
|---|---|
| INCI name | Kojic Acid↗ |
| Japanese labeling name | コウジ酸 |
| Common Japanese notations | コウジ酸, 麹酸 |
| CAS number | 501-30-4↗ |
| Origin | Fermented (originally identified as a metabolite of Aspergillus oryzae) |
| Typical functions | Quasi-drug whitening active |
| Regulatory status in Japan | Approved as a quasi-drug (医薬部外品) whitening active by 厚生労働省 (Ministry of Health, Labour and Welfare) within defined concentration ranges. |
Kojic acid was first identified by Japanese researchers as a metabolite of Aspergillus oryzae — the same koji mold central to sake, miso, and soy sauce production. Its name comes directly from this fermentation origin (kōji + -san meaning acid). It is used as a quasi-drug whitening active in Japan and as a cosmetic ingredient internationally.
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Classification
Tags below link to other ingredients sharing the same attribute, so you can pivot from one ingredient to its peers.
Product applications
Functions
Regulatory tags
Common OEM product categories
Finished-product categories where Japanese OEM manufacturers commonly formulate with this ingredient.
- Medicated whitening serums and lotions
- Spot-care products
- Soap bars (whitening positioning)
Ingredient profile
Kojic acid is a pyranone produced by various Aspergillus and Penicillium species during fermentation. Its discovery as a fermentation metabolite of Aspergillus oryzae gave the compound both its name and a particularly Japanese association.
It functions in melanin synthesis as a tyrosinase inhibitor.
OEM applications
In Japanese quasi-drug whitening products, kojic acid is one of the established approved active ingredients. Internationally, kojic acid is used in cosmetic preparations across many markets, with concentration limits varying by jurisdiction.
Regulatory classification in Japan
Approved as a quasi-drug whitening active ingredient by 厚生労働省 (Ministry of Health, Labour and Welfare) within defined concentration ranges.
Regulatory classification in other markets
| EU | Listed in CosIng under Kojic Acid. EU SCCS opinion permits cosmetic use up to 1.0 percent in face and hand products. |
|---|---|
| USA | INCI recognized. Used in cosmetic products. |
| China | Permitted per IECIC listings; verify concentration ranges. |
| Korea | Permitted under KFDA / MFDS. |
Market reference formulations
Example finished products will be added after each product's current full ingredient list has been verified.
All brand names and product names referenced anywhere on this site are the property of their respective owners. Example entries are provided for informational purposes only and do not imply endorsement.
Typical OEM use levels
Formulation ranges per finished-product application. Verify against the cited source before production.
| Application | Typical range | Regulatory limit | Notes |
|---|---|---|---|
| Quasi-drug whitening serum / lotion (Japan) | 1% | 1% per 厚生労働省 quasi-drug notification | 厚生労働省 医薬部外品有効成分通知 |
Stability & compatibility
- pH range
- pH 4–6
- Temperature
- Light-sensitive; oxidizes to brown-yellow color over time
- Incompatibilities
- Iron ions (forms colored chelates)
- Strong oxidizers
- UV exposure
Use opaque packaging and add metal chelators (EDTA / phytate). Common to pair with antioxidants to retard color shift.
Storage requirements
How the receiving OEM facility needs to handle inbound raw material.
- Temperature
- ≤20°C; refrigerated for long-term color retention
- Conditions
- Dry, sealed, opaque packaging mandatory (oxidizes to brown / yellow)
- Shelf life
- 24 months sealed; visible color shift over time even sealed
EU SCCS (欧州消費者安全科学委員会) + supplier SDS
Supply concentration
Where this ingredient comes from — useful for single-source-risk planning.
- Primary regions
- Aspergillus oryzae fermentation-derived; production scale is largest in China and Korea
- Import dependence
- Japanese supply mostly imported; domestic volume small
Alternative ingredients
Related ingredients commonly evaluated as substitutes.
Quick answers
- What is Kojic Acid?
- Kojic acid was first identified by Japanese researchers as a metabolite of Aspergillus oryzae — the same koji mold central to sake, miso, and soy sauce production. Its name comes directly from this fermentation origin (kōji + -san meaning acid). It is used as a quasi-drug whitening active in Japan and as a cosmetic ingredient internationally.
- What is the regulatory status of Kojic Acid in Japan?
- Approved as a quasi-drug (医薬部外品) whitening active by 厚生労働省 (Ministry of Health, Labour and Welfare) within defined concentration ranges.
- What products typically use Kojic Acid?
- Medicated whitening serums and lotions / Spot-care products / Soap bars (whitening positioning)
- Where does Kojic Acid come from?
- Fermented (originally identified as a metabolite of Aspergillus oryzae)
- What is the INCI / JSCI labeling name for Kojic Acid?
- INCI: Kojic Acid / JSCI: コウジ酸
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Manufacturers mentioning this ingredient
Japanese OEM factories whose published profile references this ingredient. Auto-detected from manufacturer descriptions; verify capabilities directly.
Regulatory guidance
Take the next step
FAQ for OEM buyers
Q. What is the regulatory status of kojic acid in Japan, the EU, and the US?
Japan approves it as a quasi-drug whitening active; the EU SCCS has assessed it safe at up to 1% in face/hand cosmetics; in the US it is used as a cosmetic ingredient with no specific OTC monograph status. South Korea also recognizes brightening claims at controlled levels.
Sources · Last reviewed: 2026-04-26
- 厚生労働省 (Ministry of Health, Labour and Welfare) — quasi-drug whitening actives
- SCCS Opinion on Kojic Acid (SCCS/1637/21)
Q. What is the typical Japanese quasi-drug use level?
Quasi-drug whitening formulations typically use kojic acid at around 1.0% (the validated approval level); finished product pH and packaging significantly affect color and odor stability.
Sources · Last reviewed: 2026-04-26
- 厚生労働省 (Ministry of Health, Labour and Welfare) — quasi-drug approval files for kojic acid
Q. What stability/quality issues should buyers expect?
Kojic acid is prone to discoloration (yellow-brown) and degradation in the presence of metal ions, light, and elevated pH. Chelators (EDTA, sodium phytate), antioxidants, and opaque packaging are standard countermeasures.
Sources · Last reviewed: 2026-04-26
- Industry knowledge — kojic acid formulation practice
Industry-knowledge claim — not yet pinned to a single primary source
Q. Are there allergen or sensitization concerns?
Japanese and EU safety assessments have identified contact sensitization potential at higher use levels, which is why the SCCS limit is 1% in face/hand products and excluded for body lotion. Patch testing is recommended for high-strength formulations.
Sources · Last reviewed: 2026-04-26
Use cases
Medicated whitening cream/serum
- Positioning
- Mainstream Japan quasi-drug whitening line
- Typical usage level
- 1% (Japan quasi-drug)
- Formulation notes
- Use chelators, antioxidant, and opaque packaging; pair with vitamin C derivatives for combined claims.
Sources
- Industry knowledge — kojic acid Japan formulations
Industry-knowledge claim — not yet pinned to a single primary source
Brightening soap (Asia/global export)
- Positioning
- Mass-market Asian brightening bar/liquid soap
- Formulation notes
- Common in Philippines/SE Asia exports at higher levels; check destination-market regulatory caps.
Sources
- Industry knowledge — Asian brightening soap market
Industry-knowledge claim — not yet pinned to a single primary source
Spot-treatment ampoule
- Positioning
- Targeted dark-spot serum, often combined with arbutin
- Formulation notes
- Stabilize with low pH (3.5–5.0) and chelators; airless pump packaging.
Sources
- Industry knowledge — spot-treatment ampoule formulation
Industry-knowledge claim — not yet pinned to a single primary source
EU brightening face cream
- Positioning
- Brightening positioning under EU cosmetics regulation
- Typical usage level
- ≤1.0% (face/hands per SCCS opinion)
- Formulation notes
- Only face/hand use; exclude body lotion to comply with SCCS opinion.
Sources
- SCCS Opinion SCCS/1637/21 (Kojic Acid)
Search the academic literature
Pre-filled queries for the major research databases. Opens in a new tab.
Official regulatory databases
External links to public Japanese / international regulatory authorities. We are not affiliated.
References
- Japan 医薬品医療機器総合機構 PMDA (Pharmaceuticals and Medical Devices Agency) — quasi-drug active ingredient approval registry
- EU SCCS opinion on kojic acid
Last updated: 2026-04-22. Ingredient entries are reviewed at least annually against current regulatory listings.