Synthetic hair dyes contain questionable ingredients such as PPD para-phenylenediamine and PTD toluene-2,5-diamine. These aromatic amines are hazardous to health and even carcinogenic. It is better to use 100% organic plant-based hair dyes, which contain tannic acid for skin care and strengthen the hair.
https://www.naturalscience.org/news/2025/10/smart-fact-5/
