Background and Aims Platelet rich plasma (PRP) is a source of growth factors recently introduced to treat androgenetic alopecia (AGA) with conflicting results. Our aims are to assess the efficacy of PRP in increasing hair density in males with AGA, and to investigate a correlation between positive response and each of patient's age and type and duration of AGA. Materials & Methods This before and after study included 30 males with no history of hair treatments for at least 3 months prior to our study. Each patient received 3 injections at one-month intervals. Scalp hair density of each subject was measured manually by a dermatoscope before and following 2 and 6 months of the first intervention. Data were compared to evaluate efficacy. Results Hair density was increased by 19.17% following our intervention (172.46 ± 59.04 hairs/cm2 before treatment to 205.53 ± 68.20 hairs/cm2 after 6 months) with minimal short-term side effects. Type III vertex was the least responsive pattern and no correlation was observed between positive response and either patient's age or duration of AGA. Conclusion PRP injections for men with AGA has a positive effect on hair density.
