ABSTRACT
BACKGROUND: Androgenetic alopecia (AGA) is a common yet difficult-to-treat condition, which is an important psychosocial problem. Platelet-rich plasma (PRP) therapy has been considered as a promising treatment for AGA. However, the current evidence on the efficacy of PRP for treating AGA is still controversial. This study evaluated the efficacy of PRP monotherapy in the treatment of AGA. METHODS: We searched PubMed, Embase, Cochrane Library and Web of Science to collect randomized controlled trials on use of PRP in AGA for a meta-analysis. RESULTS: Ten trials with a total 555 treatment units were identified. The hair density in PRP group was significantly higher than control group [MD = 25.09, 95%CI: 9.03-41.15, p = 0.002], but there was no significant difference in hair diameter between two groups [SMD = 0.57, 95%CI: - 0.23 to 1.38, p = 0.16]. Subgroup analyses indicated that hair density was significantly higher among the male-only trials than in the mixed-sex samples (p = 0.02). In addition, neither the split-head design nor the year of publication affected hair density (p = 0.05, p = 0.06). However, hair density was significantly higher in trials with a sample size less than 30 (p = 0.0004). CONCLUSIONS: PRP treatment increased hair density in participants with AGA, but not hair diameter. In terms of hair density, PRP elicits stronger effects in male patients. There was a trend toward differed treatment effect by gender with PRP injection, which warrants further investigation. Especially in the case of female. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors https://www.springer.com/00266 .