Platelet-Rich Plasma Monotherapies for Androgenetic Alopecia: A Network Meta-Analysis and Meta-Regression Study.

INTRODUCTION: Platelet-rich plasma (PRP) is a commonly used therapeutic option for androgenetic alopecia (AGA). Evidence syntheses for the impact of PRP on AGA has been handicapped by non-standardized protocols for its administration. We quantitatively synthesized the evidence base to determine the relative efficacy of PRP regimens with different frequencies of administration. We defined frequency as a vector of the (i) number of sessions and (ii) time interval between the sessions. METHODS: We systematically reviewed the peer-reviewed literature to obtain relevant data; we then conducted a multivariable meta-regression and network meta-analyses (NMAs). RESULTS: Twenty-five trials met our eligibility criteria; 10 unique PRP regimens were ultimately identified for use in our analyses. Our NMAs produced surface under the cumulative ranking curve (SUCRA) values that corroborated the findings of our multivariable meta-regression. The frequency of PRP sessions, chemical activation, number of centrifugations, the age and sex of the patient, and the design of PRP administration (ie, whole-head vs split-scalp) are correlated with the efficacy of PRP insofar as the mean change in total hair density at 6 months from baseline. CONCLUSIONS: For the most part, regimens’ SUCRA rankings and relative effects support that the efficacy of PRP administration increases when: (i) the number of sessions increases and (ii) the time interval between sessions decreases; we found that chemically-activated PRP (vs inactivated), double centrifugation (vs single), younger (vs older) age of treated patients, female (vs male) sex, and whole-head (vs split-scalp) administration is associated with improved PRP efficacy. Our approach rules out much confounding as the analysis of our outcome was exclusive to monotherapy at a singular timepoint. Our results may reconcile discrepant findings among previous studies and may be helpful in updating clinical practice guidelines. J Drugs Dermatol. 2022;21(9):943-952. doi:10.36849/JDD.6948.