Objective To explore the clinical efficacy of platelet-rich plasma (PRP) injection in treating androgenetic alopecia (AGA). Methods A total of 126 AGA patients from May 2024 to October 2025 treated in our hospital were retrospectively selected and divided into groups based on treatment methods. The control group (63 cases) received conventional medication, while the study group (63 cases) additionally received PRP injection. The clinical efficacy, symptom scores, hair microscopy indicators, and sex hormone levels were compared in both groups. Results In the overall effective rate, in comparison of the control group 80.95%, the study group 95.24% was higher (P < 0.05). After treatment, in comparison of the control group, hair loss, oily scalp, thinning hair, and softening hair scores in the study group were lower (P<0.05). After treatment, in comparison of the control group, hair growth rate in the study group was slower (P<0.05), hair density and follicle density were higher (P<0.05). After treatment, in comparison of the control group, testosterone level in the study group was lower (P<0.05), and estradiol level was higher (P<0.05). Conclusion PRP injection improves clinical efficacy, alleviates symptoms, and enhances hair microscopy indicators and sex hormone levels in the treatment of AGA.