Abstract Reactive oxygen species (ROS)‐triggered oxidative eustress can stimulate regenerative signaling, yet its therapeutic window remains narrow. Mitochondrial respiratory complexes and superoxide dismutase (SOD) are canonical enzymatic sources of intracellular H 2 O 2 . Here we report a biomimetic polyphenol–amino acid nanozyme (PEAs) that couples the semiquinone radical of coenzyme Q (ubiquinone) with the Arg143 residue of Zn/Cu‐SOD1. Through self‐assembling epigallocatechin gallate (EGCG) and L‐arginine (L‐Arg), PEAs enable O 2 adsorption and activation with controlled H 2 O 2 generation. The H 2 O 2 output is finely tuned by modulating the nitrogen (N) content from L‐Arg. Integrated experimental and computational analyses reveal that the N‐sites introduced by L‐Arg promote semiquinone electron delocalization, increase semiquinone abundance, thereby strengthening O 2 adsorption, facilitating electron/proton transfer, and lowering the reaction barrier for H 2 O 2 synthesis. Using the genetically encoded H 2 O 2 sensor HyPerion, this work validates the sustained intracellular modulation of H 2 O 2 by PEAs. In a mouse model of telogen effluvium, controlled H 2 O 2 delivery activates the follicular niche via Wnt/β‐catenin upregulation and Ca 2+ /calcineurin/NFAT downregulation, resulting in robust follicle activation and a non‐pharmacological approach to alopecia therapy. This polyphenol–amino acid nanozyme therefore provides a safe and effective strategy for in vivo pro‐oxidative modulation, offering a tunable H 2 O 2 ‐based platform to harness beneficial oxidative stress for tissue renewal.