November 2025 in “International Journal of Biological Macromolecules” This study introduced an eco-friendly enzymatic hair dyeing process utilizing laccase-catalyzed polymerization of hematoxylin, achieving intense, long-lasting color comparable to commercial dyes while enhancing hair strength and offering antioxidant and UV-shielding benefits.
August 2022 in “Zenodo (CERN European Organization for Nuclear Research)” This study evaluated various herbal combinations for hair coloring and found that a formulation of Henna and Indigo provided a natural reddish-brown color with better retention compared to marketed herbal hair dyes, without using synthetic agents that can cause allergic reactions.
This study evaluated various herbal blends of powdered leaves, including Henna and Indigo, for their coloring and sensitivity reactions, finding Henna and Indigo to be effective natural colorants for achieving a reddish-brown hair color with better retention than marketed herbal hair dyes.
This study developed a natural hair dye using Coreopsis tinctoria Nutt. extract, finding that it produced yellow to dark brown colors depending on the treatment, with ferrous lactate enhancing dye performance and color stability after washing.
December 2025 in “Journal of Pharma Insights and Research.” This study explains the formulation and evaluation of a natural polyherbal shampoo, which effectively colors hair and provides conditioning without the dermal and systemic toxicity risks of synthetic dyes, offering an effective alternative to conventional products.