Kojic Acid Powder – Professional Cosmetic Formulation Guide
Kojic Acid Powder is a professional water-soluble cosmetic tone-care ingredient with the INCI name Kojic Acid. It is supplied as an off-white crystalline powder for carefully controlled face and hand cosmetics designed for a more even-looking skin tone.
This Kojic Acid formulation guide covers the 1% regulatory limit for face and hand products, water-phase incorporation, pH, heat, oxidation and colour control, preservation, packaging, compatible actives, troubleshooting, stability and UK-safe cosmetic claims.
Raw-material notice: Kojic Acid Powder is a cosmetic raw ingredient, not a finished skincare product. Do not apply it neat, use it directly on skin or mix it into a finished product in the hand. To purchase it, visit the Kojic Acid product page.
Quick answer: what is Kojic Acid Powder?
Kojic Acid Powder is the water-soluble cosmetic raw material with the INCI name Kojic Acid. It is used in professionally formulated tone-care products and is particularly process-sensitive because pH, oxygen, light, heat and metal ions can affect colour and stability.
For face and hand products, the current EU maximum is 1%. This is a regulatory limit for the specified product types, not an invitation to use 1% in every product. Confirm the destination-market requirements and the current supplier documents before manufacture.
Why formulators use Kojic Acid
- Water-soluble active: suitable for aqueous serums, gels and O/W emulsions.
- Cosmetic tone-care positioning: used in formulas designed for a more even-looking skin tone.
- Low-level development: the key formulation screen is usually around 0.5–1% for face and hand products.
- Compatible with structured active systems: can be evaluated with niacinamide, Alpha Arbutin, Tranexamic Acid and Ectoin.
- Clear process requirements: controlled pH, cool-down addition, oxygen/light management and preservation are central to success.
Do not use medical, disease-treatment or guaranteed depigmentation claims for a raw cosmetic ingredient. Evaluate the finished product and the applicable claims rules.
At-a-glance technical profile
| Parameter | Formulation information |
|---|---|
| INCI name | Kojic Acid |
| CAS number | 501-30-4 |
| Physical form | Off-white crystalline powder |
| Functional class | Water-soluble cosmetic tone-care active |
| Solubility / phase | Water soluble; add to the aqueous phase |
| Face and hand product maximum | 1% in the EU; check the destination market and product type |
| Development pH | Approximately pH 4.8–5.0; keep the system within the active’s validated stability range |
| Temperature | Add below 40°C where possible |
| Packaging | Opaque, protective packaging is preferred for light-sensitive active systems |
| Preservation | Not a preservative; a complete preservation strategy is required |
Use levels and regulatory control
| Development level | Use |
|---|---|
| 0.25–0.5% | Initial compatibility and colour-stability screen |
| 0.5–1% | Common development range for face and hand products, subject to the 1% maximum |
| Above 1% | Not suitable for EU face and hand products under the current limit; check the destination market and do not exceed applicable restrictions |
Do not copy older 1–3% guidance into current product content. The current JustGlow position is the 1% maximum for EU face and hand products, with finished-product safety and regulatory assessment still required.
How to formulate with Kojic Acid
Kojic Acid is added to the water phase. Because it is sensitive to process and storage conditions, the formulator should control pH, heat, air exposure, light and trace metals.
Water-phase method
- Reserve a measured portion of deionised water.
- Weigh Kojic Acid accurately.
- Dissolve it in the water phase using controlled mixing.
- Avoid unnecessary prolonged heating.
- Prepare the rest of the emulsion or serum base.
- Add Kojic Acid below 40°C where the process permits.
- Adjust the complete formula toward approximately pH 4.8–5.0.
- Inspect colour immediately and during stability testing.
Do not assume that a clear freshly made solution will remain colourless or stable. The finished formula should be tested in its final packaging and under relevant storage conditions.
Oxidation and colour control
Kojic Acid formulas can discolour or lose quality if the formula is exposed to unsuitable pH, oxygen, light, heat or trace metals. Development controls may include:
- deionised water and clean manufacturing equipment;
- a suitable chelation or antioxidant strategy selected for the formula;
- cool-down addition below 40°C;
- final pH around 4.8–5.0 when compatible with the rest of the product;
- opaque or airless packaging;
- low headspace or packaging that limits repeated air exposure;
- stability samples retained for colour and odour comparison.
Optional systems such as phytic acid 50% liquid or ActiveProtec OX may be evaluated where compatible with the formula, but they do not remove the need for stability testing or preservation.
Kojic Acid in serums, gels and emulsions
Use a simple water-based serum as the first development format. Once the active system is stable, move to a cream or gel-cream.
Emulsion sequence
- Prepare the water and oil phases separately.
- Emulsify using the selected system.
- Cool under controlled mixing.
- Add pre-dissolved Kojic Acid below 40°C.
- Add other cool-down actives and preservative according to their instructions.
- Adjust final pH toward 4.8–5.0 if compatible.
- Fill into opaque or airless packaging and begin stability testing.
Kojic Acid is water soluble and does not belong in the oil phase. Oil-soluble ingredients such as Alpha Bisabolol or Hydra Synol DOI should be kept in the oil phase and only combined through the emulsion process.
Compatible active systems
| Ingredient | Phase | Development note |
|---|---|---|
| Niacinamide | Water phase | Common pairing; control total active load and pH |
| Alpha Arbutin | Water phase | Check combined pH, heat and regulatory limits |
| Tranexamic Acid | Water phase | Evaluate clarity, pH, colour and dissolved-solids load |
| Ethyl Ascorbic Acid | Water phase | Check vitamin C derivative stability and light protection |
| Ectoin | Water phase | Hydration-oriented support; assess viscosity and preservation |
| Alpha Bisabolol | Oil phase | Add through the oil phase; not a direct water-phase ingredient |
Combining several high-interest tone-care actives makes the formula harder to stabilise. Use a staged development approach and do not assume that a clear day-one sample is commercially stable.
Starter formulation framework
| Component | Starting range | Role |
|---|---|---|
| Kojic Acid | 0.5–1% | Water-phase cosmetic tone-care active |
| Niacinamide | Supplier-guided | Water-phase supporting active |
| Glycerin | 2–3% | Humectant |
| Phytic Acid 50% or ActiveProtec OX | Supplier-guided | Optional oxidation/metal-control development variable |
| Emulsifier or gel polymer | Supplier-guided | Structure |
| Preservative | Supplier-guided | Microbiological protection |
| Purified water | q.s. to 100% | Continuous phase |
Use a control without Kojic Acid, a 0.5% batch and a 1% batch. Compare colour, pH, viscosity, odour and stability in identical packaging.
Troubleshooting
| Observation | Possible cause | Response |
|---|---|---|
| Formula becomes yellow or brown | Oxidation, light, heat, pH, metal ions or incompatible ingredients | Review pH, chelation, packaging, water quality and process temperature |
| Powder remains visible | Insufficient dissolution or addition to a viscous phase | Pre-dissolve in water before adding to the main batch |
| Viscosity falls | pH or dissolved-solids effect on the polymer system | Check pH and compare a lower active/polymer control |
| Emulsion separates | Emulsifier/process problem or active affecting the structure | Compare with a control and review emulsification and cool-down |
| pH drifts | Late additions, buffer imbalance or inaccurate measurement | Measure after equilibration and adjust the complete formula |
| Product stings | Complete active system, pH or preservative is unsuitable | Review the whole formula and intended product claim |
Stability and packaging
- Use opaque, airless or otherwise protective packaging where appropriate.
- Monitor colour, odour, clarity, pH and viscosity at day 0, 24–48 hours, one week and longer term.
- Run cool, room-temperature and elevated-temperature tests.
- Use a suitable chelation/oxidation strategy only as part of a full stability plan.
- Validate preservative efficacy for every water-containing product.
- Do not approve the formula because it is clear and pale immediately after manufacture.
Common questions
What is the INCI name?
The INCI name is Kojic Acid.
How much Kojic Acid can I use?
For EU face and hand products, the current maximum is 1%. Use the current destination-market requirements and finished-product safety assessment.
What pH should I use?
A practical development target is approximately pH 4.8–5.0, with the complete formula kept within its validated stability range.
Can I add it below 40°C?
Yes. Cool-down addition below 40°C is preferred where the process permits.
Can I use it with Alpha Arbutin or Tranexamic Acid?
They can be evaluated together in water-phase systems, but active load, pH, colour and stability must be tested carefully.
Is Kojic Acid a preservative?
No. It is a cosmetic active and does not preserve a water-containing product.
Can I make medical or melasma claims?
No. This product is a cosmetic raw material. Use compliant cosmetic tone-care wording and substantiate finished-product claims.
Storage and handling
Keep tightly closed, dry and protected from light, heat and contamination. Use clean, dry tools. Follow the current SDS, COA and batch label for storage and shelf life.
Professional compliance reminder
The finished-product manufacturer is responsible for formula safety, claims, regulatory limits, microbiological quality, packaging compatibility and market-specific compliance. This guide is formulation education and does not replace a CPSR or professional regulatory assessment.
Buy Kojic Acid Powder
Visit the Kojic Acid Powder product page for pack sizes and current technical documents.
The product page links back to this Kojic Acid formulation guide in Ingredients A–Z.
Technical documents
Review the current JustGlow SDS and batch-specific COA before manufacture.