2,3-Dihydro-1H-indole-5,6-diol and its hydrobromide salt (see note 17).
Other
Moderate
CAS Number: 29539-03-5 - 138937-28-7
About 2,3-Dihydro-1H-indole-5,6-diol and its hydrobromide salt (see note 17).
A dihydroxyindoline hair dye precursor — gradually builds natural-looking color. Restricted to 2.0% in hair products.
Detailed Analysis
2,3-Dihydro-1H-indole-5,6-diol is an indoline derivative that acts as an auto-oxidative hair dye — it gradually darkens hair through air oxidation to form melanin-like polymers. It is restricted to 2.0% maximum in hair dye products. No GHS hazard classifications are recorded, suggesting relatively low acute toxicity compared to other hair dye chemicals. However, limited long-term safety data exists.
What It Does
Known Concerns
- ⚠ EU restricted to 2.0%
- ⚠ Hair dye chemical
- ⚠ Limited long-term data
Safety Score
Moderate
Based on EU regulatory data, published safety research, and ingredient function analysis.
References
EU CosIng Database
European Commission cosmetic ingredient registry
Check your products for 2,3-Dihydro-1H-indole-5,6-diol and its hydrobromide salt (see note 17).
Scan any cosmetic product to see if it contains this ingredient and get a full safety breakdown.
Download LuxSenseThis information is for educational purposes only and does not constitute medical advice. Always consult a healthcare professional for skin concerns or allergies.