Efficacy of Platelet-Rich Plasma Injection for The Treatment of Male Androgenetic Alopecia – A Systematic Review and Meta-Analysis of Changes in Hair Density

Background: Androgenetic alopecia (AGA) is the most common form of hair loss in men, wherein systemic androgen disorders and genetic factors lead to progressive miniaturization of hair follicles due to changes in the duration of hair growth cycle, characterized by shorter anagen phase and longer telogen phase, resulting in smaller, thinner, and less pigmented terminal hair. The main goal of treatment in AGA is to prevent the miniaturization process. The therapeutic options commonly used in the treatment of male AGA, such as topical minoxidil and oral finasteride, have yet to produce satisfactory results. Currently, many new therapeutic modalities are being developed for AGA, one of which is platelet-rich plasma (PRP). Multiple growth factors secreted by PRP are thought to support hair growth by prolonging the anagen phase, preventing apoptosis, delaying induction of the catagen phase, triggering angiogenesis and increasing follicular vascularization. Methods: A systematic literature search was performed using PubMed-MEDLINE, Cochrane library, Embase, AMED, Clinicaltrials.gov, dan WHO ICTRP with the search terms “platelet rich plasma” and (“male androgenetic alopecia” or “male pattern hair loss”). Eight RCT were included in the qualitative synthesis and seven of them were included in the meta-analysis. Results: The overall SMD in hair density was -0.889 (95% CI: -1.630 – -0.147, p<0.05) in favor of PRP treatment, indicating that PRP has significantly greater efficacy over placebo treatments in improving hair density among male patients with AGA. Conclusion: Platelet-rich plasma injection is effective in improving hair density. The addition of PRP might be considered to help improve treatment outcomes.