Platelet Rich Plasma (PRP)
While the science has not confirmed its utility with clarity, the frequency with which Platelet Rich Plasma being used, either as a stand-alone treatment or in conjunction with hair transplantation, makes it relevant and worth discussing.
Blood contains many components suspended in plasma. Red blood cells, white blood cells, and platelets are the major components. To make PRP, blood is drawn from the patient (when drawn from the patient the resultant PRP is called autologous PRP) and put through two sequential centrifugations. By spinning once to remove the red cells and then again to remove the white cells, a plasma that is rich in platelet cells is created—3 to 7 times as concentrated as in whole blood. Platelets can stimulate many kinds of growth factors and other factors that can enhance hair growth—in theory. PRP has been used in many other areas to accelerate healing and reduce pain. So, the question is, does it work to regrow hair when injected into the scalp of those experiencing androgenic hair loss or hair loss from alopecia areata?
In an article titled “The Effect of Platelet-Rich Plasma in Hair Regrowth: A Randomized Placebo-Controlled Trial” (STEM CELLS TRANSLATIONAL MEDICINE 2015;4:1–7), the effectiveness of using platelet rich plasma to regrow hair was tested on 20 subjects with androgenic hair loss. A portion of the scalp was injected with autologous PRP and another portion was injected with placebo an equal number of times. The patients then had specialized photography (called a phototrichogram) performed and evaluated by technicians who were blind to what portion of the head received placebo versus PRP. The evaluators were not involved in the treatment. The patients received three courses of therapy 1 month apart and were then followed for two years.
The results were positive in this Italian study. The authors wrote, “At the end of the 3 treatment cycles, the patients presented clinical improvement in the mean number of hairs, with a mean increase of 33.6 hairs in the target area, and a mean increase in total hair density of 45.9 hairs per cm squared compared with baseline values. No side effects were noted during treatment.”
Of significance, four patients had progressive hair loss detected at 16 months and required another course of treatment.
It must be noted that the science to validate the use of PRP has not been performed to the extent it must be to make any definitive statement about its use. The science of its effect has not been completely defined, large numbers of patients have not been tested in multiple double-blind, placebo-controlled, randomized studies, and the follow up to treatment has not been lengthy because of its recent use in the treatment of alopecia.