More even skin tone with a 1% combination
Clinical trialImproved look of spots, texture and skin tone evenness from week 2, with a melanin index down at 12 weeks. The effect comes from the combination of three actives, not from kojic acid alone4.
Kojic acid
Kojic acid is a metabolite of fungal origin that inhibits tyrosinase, an enzyme in melanin synthesis9. Since Regulation (EU) 2024/996, it is only allowed as a skin lightener, in face and hand products, at 1% maximum2. The CIR panel judges it safe up to that threshold3.
Kojic acid at a glance
Entry from our cosmetic ingredient glossary. Regulatory data from the European Commission's CosIng database1 and from Regulation (EU) 2024/9962, safety according to the CIR expert panel3. Copy the identifiers in one click for your files.
- INCI name
- KOJIC ACID
- Other names
- 5-hydroxy-2-(hydroxymethyl)-4H-pyran-4-oneCosIng chemical name1
- CAS number
- 501-30-4
- EC number
- 207-922-4
- CosIng functions
- Antioxidant, skin lightening"Antioxidant" and "bleaching" in the European nomenclature1
- Origin
- Metabolite produced by fungiObtained by fungal fermentation9
- EU status
- Restricted: Annex III, entry 375Skin lightening only, face and hand products, 1% maximum2
- Timeline
- Applicable since February 1, 2025Non-compliant products have no longer been placed on the market since that date, nor made available since November 1, 20252
- Allergen to declare
- No
What the research says
Each result shows the protocol and the level of evidence. The higher the level, the better the result carries over to a finished formula.
Clinical trialReview or consensusLaboratory
Face and hand skinSkincare
Sun spots: a disappointing result
Clinical trialThis formula showed no efficacy on solar lentigines, whereas a stabilized soy extract gave a modest lightening5.
Gradual lightening of sun spots with a combination
Clinical trialVisible lightening from 1 month of daily application, increasing over 3 months. Four actives are combined: the contribution of kojic acid itself is not isolated6.
A lightening active among 14 molecules compared
Clinical trial1% kojic acid is in the comparison, but its rank is not given in the abstract. The abstract only cites 7% ascorbic acid (second at 4 days) and 4% hydroquinone (second at 1 month)7.
Reviews, safety and stabilitySafety
Safe up to 1%: sensitization and lightening under control
ReviewKojic acid is absorbed slowly by human skin. The panel concludes that the two points of caution, sensitization and lightening, do not appear below 1%. In black-skinned guinea pigs, lightening appears at 4% but not at 1%3.
Mechanism and safety: two reviews
ReviewKojic acid inhibits tyrosinase and limits melanin formation. A 2022 review judges it safe at the concentrations tested and notes that its derivatives are offered to limit its degradation89.
An active sensitive to oxidation
LaboratoryWith sodium metabisulfite, the best formulas retain 86% (emulgel) and 76% (gel) of the kojic acid; cold storage is the most favorable. Under forced oxidation, kojic acid degrades more slowly than its dipalmitate ester1011.
This page summarizes published literature on a cosmetic ingredient. It does not describe the effect of a finished product, which depends on its formula, and it is not medical advice. Several of the clinical trials cited were run or funded by cosmetics companies; this is indicated in the sources. The clinical evidence almost always covers combinations of actives, and one of the studies cited shows no effect.
Concentrations used in studies
The colored zone marks the European limit of 1%, which applies to face and hand products. The CIR panel relies on sensitization data at 2% in a leave-on product and on lightening observed at 4% in guinea pigs. The final concentration of a formula is set with the formulator, within the framework of Regulation (EU) 2024/996.
Which products use kojic acid?
Our white label catalog includes 3 formulas with kojic acid: the key active in 3 of them, a supporting ingredient in the others. Every category can be customized (formula, fragrance, packaging).
2Face
Key active in the dark spot serum and cream, combined with alpha-arbutin, within face products allowed at 1% maximum.
1Body
Regulation (EU) 2024/996 reserves kojic acid for face and hand products: a body formula must be adapted to this scope with the formulator.
In our formulas, it is most often paired with
Licorice extract 2Sweet almond oil 2Niacinamide 2Panthenol 2Vitamin C 2Kojic acid, alpha-arbutin, vitamin C or niacinamide?
Four actives often combined in skin tone care. They do not exclude each other and are often combined in the same formula.
| Kojic acid | Alpha-arbutin | Vitamin C | Niacinamide | |
|---|---|---|---|---|
| Main role | Skin lightening, antioxidant1 | Skin lightening and conditioning2 | Radiance, antioxidant protection | Skin tone, barrier, shine |
| In the formula | Sensitive to oxidation, antioxidants useful10 | Hydroquinone must remain at the level of unavoidable traces2 | Oxidizes with air and light, needs protective packaging | Stable, easy to formulate in the water phase |
| EU regulation | 1% maximum, face and hands only2 | 2% in face cream, 0.5% in body lotion2 | No restriction for ascorbic acid | No restriction |
| Who it suits | Skin tone care for face and hands | Skin tone care, face and body | Dull skin | General public, sensitive skin included |
Frequently asked questions about kojic acid
What is kojic acid?
What percentage of kojic acid is allowed in cosmetics?
What are the benefits of kojic acid?
Is kojic acid safe, and does it have side effects?
Can you use kojic acid with alpha-arbutin?
Yes, it is a common pairing in skin tone care. Both actives are regulated by Regulation (EU) 2024/996: 1% for kojic acid, 2% in face cream for alpha-arbutin2. The stability of the final formula is checked through lab testing.
Can you use kojic acid on the body?
No, not in a body product: the regulation limits kojic acid to face and hand products2. Non-compliant products have no longer been made available on the European market since November 1, 2025.
Can you manufacture a dark spot cream with kojic acid for my brand?
Yes. Our ISO 22716 certified lab offers 3 kojic acid formulas (serum, cream) that you can customize, or a custom formula. The concentration and the products concerned remain within the framework of Regulation (EU) 2024/996. Samples are free.
Sources
Peer-reviewed studies and official regulatory sources, checked on November 2, 2026.
- European Commission. CosIng, entry KOJIC ACID (CAS 501-30-4, EC 207-922-4). ec.europa.eu/growth/tools-databases/cosing
- Commission Regulation (EU) 2024/996 of 3 April 2024 amending Regulation (EC) No 1223/2009 (vitamin A, alpha-arbutin, arbutin and other substances) : Annex III, entries 375 (kojic acid) and 377 (alpha-arbutin). eur-lex.europa.eu
- Burnett CL, Bergfeld WF, Belsito DV, et al. Final report of the safety assessment of kojic acid as used in cosmetics. Int J Toxicol. 2010;29(6 Suppl):244S-273S. doi:10.1177/1091581810385956
- Desai S, Ayres E, Bak H, et al. Effect of a tranexamic acid, kojic acid, and niacinamide containing serum on facial dyschromia: a clinical evaluation. J Drugs Dermatol. 2019;18(5):454-459. PMID 31141852
- Hermanns JF, Petit L, Piérard-Franchimont C, et al. Assessment of topical hypopigmenting agents on solar lentigines of Asian women. Dermatology. 2002;204(4):281-286. doi:10.1159/000063359
- Piérard GE, Seité S, Rougier A, Quatresooz P. Analytic assessment under ultraviolet light of actinic lentigines under bleaching treatment. J Cosmet Dermatol. 2011;10(2):104-109. doi:10.1111/j.1473-2165.2011.00551.x
- Muller B, Flament F, Jouni H, et al. A Bayesian network meta-analysis of 14 molecules inhibiting UV daylight-induced pigmentation. J Eur Acad Dermatol Venereol. 2024;38(8):1566-1574. doi:10.1111/jdv.19910L'Oréal
- Zilles JC, Dos Santos FL, Kulkamp-Guerreiro IC, Contri RV. Biological activities and safety data of kojic acid and its derivatives: a review. Exp Dermatol. 2022;31(10):1500-1521. doi:10.1111/exd.14662
- Saeedi M, Eslamifar M, Khezri K. Kojic acid applications in cosmetic and pharmaceutical preparations. Biomed Pharmacother. 2019;110:582-593. doi:10.1016/j.biopha.2018.12.006
- Khadivi Y, Shakeri S, Arjmandmazidi S, et al. The effect of emulgel preparation on the stability of kojic acid in the topical anti-hyperpigmentation products. J Cosmet Dermatol. 2024;23(6):2145-2155. doi:10.1111/jocd.16254
- Tazesh S, Tamizi E, Siahi Shadbad M, et al. Comparative stability of two anti-hyperpigmentation agents: kojic acid as a natural metabolite and its di-palmitate ester, under oxidative stress; application to pharmaceutical formulation design. Adv Pharm Bull. 2022;12(2):329-335. doi:10.34172/apb.2022.031
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