Kojic Acid: Cosmetic Uses, Use Levels and Safety
Kojic acid is a white to off-white crystalline powder produced by fermentation with certain fungi, such as Aspergillus species. It is used in soaps, creams and serums aimed at uneven skin tone, usually at about 1% of the formula. It discolours in light and air, so it needs careful storage.
Last updated 7 Nov 2026
Specifications
- Formula
- C6H6O4
- CAS number
- 501-30-4
- Grades
- Cosmetic
Products and pack sizes
| Product | Grade | Pack | Price (incl. GST) | ₹ per kg |
|---|---|---|---|---|
| Kojic Acid | Cosmetic | — | ₹299 | — |
What is kojic acid?
Kojic acid is an organic compound made by several fungi, notably Aspergillus oryzae, the mould used in making sake and soy sauce. It is produced commercially by fermentation and sold as a powder for cosmetics.
- Chemical name: 5-hydroxy-2-(hydroxymethyl)-4H-pyran-4-one
- Formula: C6H6O4
- CAS number: 501-30-4
- Molar mass: 142.11 g/mol
- Melting point: about 152 to 155 °C
- Solubility: dissolves in water and alcohol
It slowly turns yellow or brown when exposed to light, air, heat or iron.
Grades and pack sizes at Azlok
Azlok lists kojic acid in its cosmetic raw ingredients range for soap, cream and serum makers. The pack size is on the product page. Because you use about 1% in a formula, a small pack makes many batches. See today's price per kg.
Common uses
- Kojic acid soaps and cleansing bars
- Creams, lotions and serums aimed at uneven skin tone
- Some food uses abroad and research uses, outside the scope of this cosmetic pack
Kojic acid dipalmitate is a related oil-soluble ester that handles light and heat better. It is a different ingredient, so don't swap one for the other at the same percentage.
Azlok does not make any claim about results on skin. How a finished product performs depends on the whole formula.
How to use it
A typical use level in leave-on cosmetics is about 1%, which is also the level European safety reviewers assessed for face and hand creams. That is 10 g per kg of finished product.
- Dissolve the powder in the water phase or a small amount of warm water, below about 40 °C if possible.
- Add it to emulsions after they have cooled.
- Keep the product's pH mildly acidic, around 4 to 5.5, where kojic acid is more stable.
- Pack in opaque, airtight containers.
Expect slow yellowing over time; that is the kojic acid oxidising. Patch test every finished product on the inner arm for 24 hours, as kojic acid can cause irritation or allergy in some people. Advise users to wear sunscreen.
Finished cosmetics sold in India need to meet BIS and CDSCO requirements, so if you sell what you make, keep batch records and check the rules that apply to your product.
Safety and storage
- Wear gloves and avoid breathing the dust when weighing.
- Avoid contact with eyes; rinse with water if it happens.
- Store in a tightly closed, opaque container in a cool, dry place. Light, air, heat and moisture discolour it.
- Use plastic or glass tools, not iron.
- Keep away from children.
Choosing the right grade and pack
Buy only what you will use in a few months, because opened powder discolours. If the powder is already yellow or brown when you open it, it has oxidised; contact the seller before using it. Small makers do well with a small pack; soap and cream units with regular production can buy more and keep it sealed in smaller portions. For 25 kg and above, use the bulk inquiry form.
Frequently asked questions
- How much kojic acid should I add to cream or soap?
- A typical level is about 1% of the finished product, which is 10 g per kg. Higher amounts increase the chance of irritation and discolouration. Always patch test the finished product on the inner arm for 24 hours.
- Why is my kojic acid cream turning yellow?
- Kojic acid oxidises in light, air and heat, and reacts with iron, which turns products yellow or brown. Keep the pH mildly acidic, add it after cooling, use opaque airtight packs and store them away from sunlight.
- Is kojic acid powder soluble in water?
- Yes. Kojic acid dissolves in water and alcohol, so it goes into the water phase of creams and lotions or into soap water. Gentle warmth helps, but avoid long heating.
- Is kojic acid natural?
- Kojic acid is made by certain fungi, and the commercial material is generally produced by fermentation. Whether a given lot is fermented or made another way depends on the manufacturer, so check with the supplier if your label claims depend on it.
- Is kojic acid safe for everyone?
- No cosmetic ingredient suits everyone. Kojic acid can cause irritation or allergic reactions in some people. Keep to typical levels around 1%, patch test, avoid broken skin, and stop use if redness or itching appears.
- Can I add kojic acid to cold process soap?
- Some soap makers do, but the high pH of fresh soap tends to discolour kojic acid, and the bar may turn yellow or brown. Many makers add it to melt-and-pour base instead. Patch test any finished bar.