Background: Wnt proteins are known to control cell fate decisions and cell proliferation. In this regard, Wnt/β -catenin signaling regulates hair growth and the hair shaft structure in hair follicle cell and dermal papilla cells (DPCs). This signaling pathway could be inhibited by oxidative stress in hair follicles. Objectives: In this study, the association of hair follicle and dermal papilla cells with H₂O₂ was investigated. Methods: The followings were measured under different H₂O₂ concentrations to determine experimental concentration: The length of human hair follicle ex vivo, and the cultured rat DPCs viability by MTT assay. Thereafter the expression of GSK3β, β-catenin and CyclinD1 in rat DPCs were semi-quantified by Western blot, as well as by real time PCR under H₂O₂ treated condition. Likewise, β-catenin in human DPCs, was measured after H₂O₂ treatment. Results: H₂O₂ inhibited growth of hair follicle and dermal papilla cells, by downregulating Wnt/β-catenin pathway. Under H₂O₂ condition, the expression of GSK3β, β -catenin, and CyclinD1 were decreased, in a dose dependent manner. Conclusion: H₂O₂ suppressed hair growth by inhibiting Wnt/β-catenin signal pathway.