OBJECTIVE: To investigate the role and mechanisms of Erianin in treating alopecia areata. METHODS: A C3H/HeJ AA mouse model was established using skin transfer or adoptive T-cell transfer. All mice received either systemic or topical treatments. Photographic documentation was used to monitor hair growth, which was quantified using G*Power software. Infiltrating inflammatory markers in the skin were assessed using immunofluorescence staining, and the infiltrating immune cell populations in the skin and subcutaneous draining lymph nodes (SDLNs) were analyzed using flow cytometry. RESULTS: Erianin effectively inhibited the function of effector T cells, significantly suppressing Alopecia Areata (AA) in C3H/HeJ transplanted mice. It also reversed systemic manifestations of AA and effectively promoted hair growth in AA mice. CONCLUSION: Erianin demonstrates a potent therapeutic effect on AA, primarily through modulation of T cell immune function.