Kojic acid in skin care

Kojic acid in cosmeceutical skin care products

Kojic acid is a tyrosinase inhibitor used to lighten skin and treat hyperpigmentation.

The best kojic acid products are serums, toners, lotions, and creams.

Best kojic acid skin care products

Dermatologist-recommended skin lightening products with kojic acid are combined with other skin lightening ingredients.

The 5 best kojic acid products for the face are:

  1. Biopelle Brightening KNR Serum
  2. Derma Made Mela Fade
  3. SkinCeuticals Discoloration Defense
  4. La Roche-Posay Glycolic B5 10% Serum
  5. PCA Skin Pigment Gel HQ Free

Shop for the best kojic acid serum

Click image below to buy kojic acid serums



What does kojic acid do to your face?

Kojic acid has many skin benefits.

Lightens dark spots

Treats hyperpigmentation

Improves melasma



Best products

The strongest kojic acid products have more than 1%, they are more likely to cause side effects.

  • It is hydrophilic.
  • This means it is most effective in toners, essences, mists, gels and serums.
  • It is best when used in leave-on products.
  • This ingredient isn't the best in soaps because it rinses off too quickly.
  • It can also be found in lotions and moisturizers.
  • Kojic acid oils are not very effective.
  • It has minimal efficacy in oils and heavy fatty acid rich creams because it is hydrophilic.
  • Kojic acid pads are effective.

Skin care routines

Kojic acid is poorly absorbed into the skin. The skin care routine order should be designed to increase skin penetration of kojic acid.

How to layer your regimen

Using the wrong cleanser and moisturizer can prevent kojic acid from getting into the skin. They way you layer products with kojic acid is important.

Here are some tips about layering kojic acid:

Combine kojic acid with hydroxyacids such as glycolic acid

Use hyaluronic acid serum in the same skin car eregimen

Use with retinoids and corticosteroids

Hydroxyacids loosen attachments between skin cells allowing increased absorption. These acids also help keep the skin pH lower which increases efficacy of kojic acid on the skin.

Lee et al. reported on derivatives of kojic acid displaying increased efficiency through increased penetration into the skin, however there are not any commercially available kojic acid derivatives that we could find on the market. (3)

In two separate studies, kojic acid combined with glycolic acid was shown to be more effective when compared with 10% glycolic acid and 4% HQ for the treatment of hyperpigmentation.(33,34)

A study by Lim compared the effect of a gel containing 10% glycolic acid and 2% HQ with and without 2% kojic acid.33 The result was that the addition of kojic acid to the gel further improved melasma.


Kojic acid is often used in in-office chemical peels to even skin tone.

It may also be found in masks and peel pads to use at home.

How to use kojic acid soap?

Kojic acid soap, cleansers and face wash are not very effective because the contact time with the skin is not long enough to cause skin lightening.

Kojic acid soap is safe, but not worth the price.

Even if you are using the kojic acid soap from CVS, it is still a waste of money.

We suggest using a glycolic acid cleanser instead and following it with a serum containing kojic acid.

But- if you want to be certain the products you buy are right for your skin type, take the quiz so we can guide you.

Skin lightening

Kojic acid is a tyrosinase inhibitor and an exfoliant.

It decreases tyrosinase activity by chelating copper.

How long does it take for kojic acid to lighten skin?

Tyrosinase inhibitors like kojic acid take 12-16 weeks to lighten dark spots on the skin.

If you are not improved in 3 months- you need to take a holiday from kojic acid for 2- 4 weeks and then restart.

Is kojic acid a clean ingredient?

Yes kojic acid is considered a clean ingredient and has no bad effects on marine life or the environment,

Is kojic acid a natural ingredient?

Kojic acid is produced by various species of Aspergillus, Acetobacter, and Penicillium.

Although kojic acid comes from a fungus, it is made in the lab and is not considered a natural ingredient.

Chemical structure of kojic acid

Kojic has a similar chemical structure to hydroquinone.

If you are allergic to hydroquinone- you may be allergic to kojic acid.


Kojic acid for Melasma

Kojic acid can be used for melasma.

However, melasma is hard to get rid of permanently and using kojic acid alone sisnot enough.

You need an entire skin care routine dedicated to focusing on melasma to get the best results. Kojic acid is just one of many ingredients found in melasma skin care treatment products.

We can help you build a skin care routine for your Baumann Skin type.

Kojic acid for dark spots

Kojic acid is a treatment for dark spots that is very similar to hydroquinone.

It lightness dark spots by:

preventing the production of melanin

exfoliating away darkly pigmented skin cells

Kojic acid for acne

Kojic acid can help clear acne because it:

lowers skin pH

kills acne bacteria


lightens dark acne scars (these are not true scars but are hyperpigmentation which will go away.)


Can kojic acid lighten skin permanently?

No the effects of kojic acid are temporary.

A few days after stopping kojic acid, the tyrosinase enzyme becomes functional again.

This is why kojic acid needs to be used 1-2 times a day.

Is kojic acid the best ingredient for you?

It depends upon your Baumann Skin Type

How long does it take for kojic acid to lighten the skin?

A skin care routine customized for your skin type can take 8-16 weeks to clear hyperpigmentation.

You must think of every step in the routine for best results because some moisturizers can inactivate kojic acid.

If your dark spots don't clear in 3 months read this.

Is kojic acid safe?

Unless you are allergic, kojic acid is safe.

Kojic acid safety

The EWG scores kojic acid as a 6-7 but it is unclear why it received this poor rating.

Kojic acid has been extensively used in foods, and there have been many reports on its oral safety.

Kojic acid is used in food to prevent browning and to promote reddening of unripe strawberries.

It seem to be safe orally. Only one Japanese study showed toxicity resulting from an oral dose which was associated with the occurrence of hepatocellular tumors in p53-deficient mice.(27)

Kojic acid should not be injected. Convulsions may occur if kojic acid is injected.30

Kojic acid 4% is much more likely to cause side effects when used topically on skin.

Most kojic acid serums are 1%-2%.


Kojic acid side effects

The side effects seen with kojic acid are:

  • allergy
  • contact dermatitis
  • stinging
  • irritation
  • rash
  • over-exfoliation when combined with other exfoliants.


Can kojic acid cause a skin allergy or irritate skin?

Yes. Kojic acid is a common skin allergen.

Topical kojic acid can cause allergies and irritation(26,31) especially in formulations using a 2.5% concentrations of kojic acid.

For this reason a concentration of 1% is usually used, but there have been reports of sensitization to 1% creams as well.34

You are more likely to be allergic to kojic acid when you have a hydroquinone allergy.

Does kojic acid cause cancer?

Kojic acid is very similar to hydroquinone. However, it has never been reported to cause cancer.

When to use kojic acid in my skin care routine?

Kojic acid should be used in step 3 of the morning and evening skin care routine.

However, this may vary depending on your Baumann Skin Type.

Kojic acid should be sued before a moisturizer and before retinol.

In some cases it may be included in a retinol or moisturizer.

Let us help you build a skin care routine and see if kojic acid is right or your skin type.

We will give you a step by step routine so you will know exactly when to use kojic acid.

Image of aspergillis is used with permission from wikicommons

References, evidence-based studies, and best peer reviewed publications about kojic acid:

  1. Baumann L. Ch 37 in Cosmeceuticals and Cosmetic Ingredients (McGraw Hill 2015)
  2. Phasha, V., Senabe, J., Ndzotoyi, P., Okole, B., Fouche, G., & Chuturgoon, A. (2022). Review on the use of kojic acid—A skin-lightening ingredient. Cosmetics, 9(3), 64.
  3. Lee YS, Park JH, Kim MH, et al. Synthesis of tyrosinase inhibitory kojic acid derivative. Arch Pharm Chem Life Sci. 2006;339:11.
  4. Prignano F, Ortonne JP, Buggiani G, et al. Therapeutical approaches in melasma. Dermatol Clin. 25:337, 2007.
  5. Bhat R, Hadi SM. Photoinactivation of bacteriophage lambda by kojic acid and Fe(III): role of oxygen radical intermediates in the reaction. Biochem Mol Biol Int. 32:731, 1994.
  6. Lee YS, Park JH, Kim MH, et al. Synthesis of tyrosinase inhibitory kojic acid derivative. Arch Pharm Chem Life Sci. 339:11, 2006.
  7. Bentley R. From miso, saké and shoyu to cosmetics: a century of science for kojic acid. Nat Prod Rep. 23:1046, 2006.
  8. Cabanes J, Chazarra S, Garcia-Carmona F. Kojic acid, a cosmetic skin whitening agent, is a slow-binding inhibitor of catecholase activity of tyrosinase. J Pharm Pharmacol. 46:982, 1994.
  9. Grimes PE. Management of hyperpigmentation in darker racial ethnic groups. Semin Cutan Med Surg. 28:77, 2009.
  10. Fuyuno I. Spotlight turns on cosmetics for Asian skin. Nature. 432:938, 2004.
  11. Draelos ZD. Skin lightening preparations and the hydroquinone controversy. Dermatol Ther. 20:308, 2007.
  12. Hira Y, Hatae S, Inoue T, et al. Inhibitory effects of kojic acid on melanin formation. In vitro and in vivo studies in black goldfish. J Jpn Cosmet Sci Soc. 6:193, 1982.
  13. Gillbro JM, Olsson MJ. The melanogenesis and mechanisms of skin-lightening agents—existing and new approaches. Int J Cosmet Sci. 33:210, 2011.
  14. Uher M, Brtko J, Rajniakova O, et al. Kojic acid and its derivatives in cosmetics and health protection. Parfuem Kosmet. 74:554, 1993.
  15. Burdock GA, Soni MG, Carrabin IG. Evaluation of health aspects of kojic acid in food. Regul Toxicol Pharmacol. 33:80, 2001.
  16. Halder RM, Richards GM. Management of dyschromias in ethnic skin. Dermatol Ther. 17:151, 2004.
  17. Halder RM, Richards GM. Topical agents used in the management of hyperpigmentation. Skin Therapy Lett. 9:1, 2004.
  18. Balaguer A, Salvador A, Chisvert A. A rapid and reliable size-exclusion chromatographic method for determination of kojic dipalmitate in skin-whitening cosmetic products. Talanta. 75:407, 2008.
  19. Curtis PJ. Chemical induction of local reddening in strawberry fruits. J Sci Food Agr. 28:243, 1977.
  20. Parvez S, Kang M, Chung H-S, et al. Survey and mechanism of skin depigmenting and lightening agents. Phytother Res. 20:921, 2006.
  21. Lim JT. Treatment of melasma using kojic acid in a gel containing hydroquinone and glycolic acid. Dermatol Surg. 25:282, 1999.
  22. Lynde CB, Kraft JN, Lynde CW. Topical treatments for melasma and postinflammatory hyperpigmentation. Skin Therapy Lett. 11:1, 2006.
  23. Cayce KA, McMichael AJ, Feldman SR. Hyperpigmentation: an overview of the common afflictions. Dermatol Nurs. 16:401, 2004.
  24. Piamphongsant T. Treatment of melasma: a review with personal experience. Int J Dermatol. 37:897, 1998.
  25. Serra-Baldrich E, Tribo MJ, Camarasa JG. Allergic contact dermatitis from kojic acid. Contact Dermatitis. 39:86, 1998.
  26. Nakagawa M, Kawai K, Kawai K. Contact allergy to kojic acid in skin care products. Contact Dermatitis. 32:9, 1995.
  27. Takizawa T, Mitsumori K, Tamura T, et al. Hepatocellular tumor induction in heterozygous p53-deficient CBA mice by a 26-week dietary administration of kojic acid. Toxicol Sci. 73:287, 2003.
  28. Picardo M, Carrera M. New and experimental treatments of cloasma and other hypermelanoses. Dermatol Clin. 25:353, 2007.
  29. Higa Y, Kawabe M, Nabae K, et al. Kojic acid – absence of tumor-initiating activity in rat liver, and of carcinogenic and photo-genotoxic potential in mouse skin. J Toxicol Sci. 32:143, 2007.
  30. Lee YS, Park JH, Kim MH, et al. Synthesis of tyrosinase inhibitory kojic acid derivative. Arch Pharm. 339:111, 2006.
  31. Nakayama G, Watanabe N, Nishioka K, et al. Treatment of chloasma with kojic acid cream. Jpn J Clin Dermatol. 36:715, 1982.
  32. Kim DH, Hwang JS, Baek HS, et al. Development of 5-[(3-aminopropyl)phosphinooxy]-2-(hydroxymethyl)-4H-pyran-4-one as a novel whitening agent. Chem Pharm Bull. 51:113, 2003.
  33. Ellis DA, Tan AK, Ellis CS. Superficial micropeels: glycolic acid and alpha-hydroxy acid with kojic acid. Facial Plast Surg. 11:15, 1995.
  34. Garcia A, Fulton JE Fr. The combination of glycolic acid and hydroquinone or kojic acid for the treatment of melasma and related conditions. Dermatol Surg. 22:443, 1996.
  35. Ferioli V, Rustichelli C, Pavesi G, et al. New combined treatment of hypermelanosis: analytical studies on efficacy and stability improvement. Int J Cosmet Sci. 23:333, 2001.
  36. Draelos ZD, Yatskayer M, Bhushan P, et al. Evaluation of a kojic acid, emblica extract, and glycolic acid formulation compared with hydroquinone 4% for skin lightening. Cutis. 86:153, 2010.
  37. Leyden JJ, Shergill B, Micali G, et al. Natural options for the management of hyperpigmentation. J Eur Acad Dermatol Venereol. 25:1140, 2011.
  38. Mitani H, Koshiishi I, Sumita T, et al. Prevention of the photodamage in the hairless mouse dorsal skin by kojic acid as an iron chelator. Eur J Pharmacol. 411:169, 2001.

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