Commentary on a Randomized Placebo-Controlled, Double-Blind, Half-Head Study to Assess the Efficacy of Platelet-Rich Plasma on the Treatment of Androgenetic Alopecia

The study conducted by Alves and Grimalt aimed to assess the efficacy of platelet-rich plasma (PRP) on the treatment of androgenetic alopecia (AGA). The study involved 22 patients with AGA who received a total of 3 treatments at monthly intervals to 2 symmetrical areas on each side of the scalp with injections of either saline or activated PRP. Phototrichogram assessments were obtained at baseline, 3, and 6 months. Compared to baseline, PRP resulted in a significant increase in total hair density and terminal hair density at 6 months; however, only terminal hair density was found to be significantly increased (just below 10%) when PRP was compared with placebo. The authors also analyzed the data based on demographics and demonstrated a significant therapeutic response in hair density versus placebo in men, patients <40 years of age, onset of AGA ≥ the age of 25, positive family history, and AGA duration of greater than 10 years. The study is noteworthy as it included equal numbers of men and women, and it used a half-head design comparing symmetrical left and right target areas, which were tattooed for accurate localization of blinded phototrichogram assessments.