As the number of individuals experiencing hair loss has increased in recent years, interest in specialized products and therapeutic approaches for its treatment has also grown. Hair loss occurs when the hair growth cycle becomes shortened, the proportion of hair follicles in the telogen phase increases, and excessive shedding takes place. It can be caused by various factors, stress, androgen imbalance, and genetic predisposition. Although finasteride and minoxidil have been approved by the U.S. Food and Drug Administration (FDA) for the treatment of hair loss, their clinical use is limited due to potential side effects. Consequently, the development of new hair growth–promoting agents is actively being pursued. This study aimed to investigate the effects of extract on androgenetic alopecia and its potential to alleviate hair growth inhibition. The cytotoxicity and biological activity of the extract were evaluated using cell proliferation assays, a DCF-DA assay, a wound healing assay, ALP staining, JC-1 assay, live-cell ATP assay, and real-time qPCR. The results demonstrated that PARE exerted hair growth–promoting effects comparable to those of the positive control, minoxidil, by restoring cell migration, reducing reactive oxygen species (ROS) production, and recovering ALP levels. These findings suggest that Phragmites australis root extract (PARE) has considerable potential as a therapeutic agent for hair loss and as a functional cosmetic ingredient.