Evaluation of platelet-rich plasma as a treatment for androgenetic alopecia: A randomized controlled trial

Platelet-rich plasma (PRP) shows promise as an androgenetic alopecia (AGA) treatment.To conduct a randomized placebo-controlled split-scalp study to investigate the effects of PRP on hair regrowth and thickness.Two 7.6-cm × 7.6-cm squares were tattooed on the scalps of 35 study participants with AGA. Areas were randomly assigned to intradermal injection with PRP or saline. Participants received 3 monthly treatment sessions with evaluation 3 months after the final treatment.Hair density in the PRP-treated area was significantly increased compared with baseline at all visits. At the final assessment, hair density in PRP-treated areas increased from 151 ± 39.82 hairs/cm2 at baseline to 170.96 ± 37.14 hairs/cm2, a mean increase of approximately 20 hairs/cm2 (P < .05). However, hair density in placebo-treated areas also increased from 151.04 ± 41.99 hairs/cm2 to 166.72 ± 37.13 hairs/cm2 (P < .05). There was no significant difference in hair density change between the 2 groups (P > .05). No serious adverse events were reported.Possible PRP diffusion due to split-scalp study design as well as microinjections causing microinjury to both sides.PRP may have benefit in increasing hair density.