Horseradish Peroxidase (HRP) is a heme-containing oxidoreductase enzyme extracted from the roots of the horseradish plant (Armoracia rusticana). Biochemically, it catalyzes the oxidation of organic substrates using hydrogen peroxide as an electron acceptor, generating reactive intermediates that can participate in downstream reactions. While HRP is best known in biotechnology and diagnostics (e.g., ELISA and Western blotting) for its ability to generate colorimetric or chemiluminescent signals, patented formulations have explored its use in cosmetic and dermo-pharmaceutical compositions to mitigate cutaneous oxidative stress. By catalyzing redox reactions that neutralize oxygen radical species generated by UV exposure, pollution, and normal metabolic processes, HRP-containing cosmetic systems can theoretically assist in preventing and repairing oxidative damage to the skin, supporting resilience against environmental aggressors that contribute to visible aging and barrier compromise.

In the context of haircare, direct evidence for HRP’s functional benefits is limited in the publicly available literature, but its enzymatic activity and capacity to catalyze oxidative reactions suggests potential roles in modulating reactive oxygen species on the scalp and potentially supporting scalp homeostasis when integrated via controlled delivery systems. Enzymatic systems in haircare have been investigated for scalp microbiome modulation and conditioning improvements, and HRP could serve as a biocatalytic agent in advanced or niche formulations if appropriately stabilized and delivered. Enzymatic ingredients often require specific carriers or encapsulation to retain activity in cosmetic formulations, and ongoing research underscores the importance of biotechnology-driven functional ingredients in emerging personal care products.