Abstract: Objective: To evaluate the efficacy and safety of platelet-rich plasma injection in the treatment of androgenetic alopecia. Methods: The randomized controlled trials on platelet-rich plasma injection in the treatment of androgenetic alopecia were searched in CNKI, Wanfang Database, CQVIP, Sinomed Database, Pubmed, Cochrane Library, Embase, Web of Science from inception to May, 2020. Two reviewers screened literature, extracted data, and assessed risk bias of included researches. Meta-analysis was performed by RevMan 5.3 software. Results: A total of 10 studies involving 212 patients were included. Meta-analyses showed that the hair density of was higher in the patients treated with platelet-rich plasma than in control group, (WMD=29.39，95% CI=1.89-56.89，P=0.04). The most common adverse reaction was pain，followed by erythema, ecchymosis and edema. There were no serious adverse events in both groups. Conclusion: Platelet-rich plasma injection can improve hair density with no serious adverse events.

Key words: platelet-rich plasma, androgenetic alopecia, systematic review, meta-analysis