BACKGROUND Androgenetic alopecia (AGA) affects up to 80% of men and 50% of women throughout their lifetime, causing significant discomfort. Minoxidil, finasteride, and low-level laser light therapy are the only Food and Drug Administration-approved treatments for AGA, and they have shown positive results in randomized controlled trials and meta-analyses. However, their efficacy is limited, and new therapies are needed. Injection of platelet-rich plasma (PRP), a minimally invasive technique, has been described by several authors as a promising treatment for AGA. Although many studies report beneficial effects of PRP on AGA, there is no standardized practice for PRP preparation and administration or a standard method to evaluate results. OBJECTIVE The aim of this study was to evaluate the efficacy of manually prepared PRP in the treatment of male AGA. METHODS We treated 20 male patients with AGA with 3 monthly injections of PRP and analyzed results by TrichoScan®. RESULTS In this study, there was no statistically significant improvement in hair count or proportion of anagen hairs. CONCLUSIONS This lack of response could be related to any of the variables during PRP preparation described above and also to the limited number of patients in the study.