OBJECTIVE To evaluate the efficacy of platelet-rich plasma (PRP) in the treatment of androgenetic alopecia, as well as establish an effective treatment protocol and optimal PRP preparation procedure. METHODS We searched the PubMed, Scopus, Embase, Cochrane, CNKI, and Wanfang databases from inception to October 29, 2021, using PROSPERO's International Prospective Register of Systematic Reviews (registration ID: CRD42022295921). RESULTS The original
literature search revealed 215 reviews; after duplication removal, 89 papers were eliminated, 95 were eliminated after reading the titles and abstracts, and eventually, 28 articles were included after reading the complete text. CONCLUSIONS PRP treatment for androgenetic alopecia is effective, and we recommend the following: (1) a PRP volume of at least 0.05 ml/cm(2) , preferably 0.1 ml/cm(2) ; (2) at least three consecutive treatments at an interval of 1 month; (3) intensive therapy is beneficial and can be provided from 3 to 6 months after continuous treatment; (4) objective indicators such as hair diameter, hair count; (5) long-term follow-up.