Abstract
BACKGROUND: Androgenetic alopecia (AGA) is the most common cause of progressive hair loss, significantly affecting quality of life. Current therapies, such as minoxidil, finasteride, and hair transplantation, show variable efficacy and may be associated with adverse effects. Platelet-rich plasma (PRP), an autologous preparation enriched with platelets and growth factors, has recently gained attention as a regenerative option for hair restoration. OBJECTIVE: This review summarizes advances in PRP therapy for AGA, focusing on preparation techniques, mechanisms of action, clinical efficacy, and safety, and provides recommendations for protocol optimization and future research. METHODS: A systematic search of PubMed, Web of Science, Embase, Cochrane Library, and CNKI was conducted for studies published between 2000 and 2025. Eligible articles included randomized controlled trials, cohort studies, case-control studies, and meta-analyses evaluating PRP preparation methods or therapeutic outcomes. Study quality was appraised using the Cochrane Risk of Bias, ROBINS-I, and GRADE frameworks. RESULTS: PRP promotes follicular regeneration through angiogenesis and activation of Wnt/β-catenin, MAPK, Akt/ERK, and Notch signaling pathways. Clinical trials demonstrate improved hair density, thickness, and patient satisfaction, particularly when PRP is combined with minoxidil, microneedling, or laser therapy. Reported adverse events are mild and transient, such as localized pain or erythema. Nevertheless, heterogeneity in centrifugation, activation, and delivery protocols contributes to inconsistent outcomes across studies. CONCLUSION: PRP represents a promising, safe, and minimally invasive therapy for AGA. Establishing standardized preparation protocols and conducting large-scale randomized studies are essential to confirm long-term efficacy and integrate PRP into routine, personalized AGA management.