One of the exciting uses of platelet-rich plasma (PRP) injections is for alopecia. Though it is generally used in combination with other treatments for hair, it has also been shown to work as as a stand-alone treatment option.
Within each dormant hair shaft there are stem cells responsible for the hair’s growth cycle. These areas do not contain pigment or melanin. Rather, they are responsible for the production of hair follicle cells within the hair matrix. Platelet-rich plasma (PRP), when introduced to the scalp, will trigger a number of biological activities through the release of glycoproteins, specifically activating KGF/FGF-7 (keratinocyte growth factor, or fibroblast growth factor 7). KGF/FGF-7 is a paracrine mediator of epithelial cell growth, including hair. CD34+ cells and other cytokines (SDF-1α) attract additional stem cells to the damaged follicle and regeneration site. There are other growth factors released within the PRP which help with differentiation, proliferation, and inducing other intracellular events. It is believed that these various biological activities and events will activate a dormant hair follicle and allow for new hair growth.
So why doesn’t PRP work for all patients suffering from thinning hair or patterned baldness? There are medical conditions and reasons for thinning and balding hair that can cause the stem cells in some hair follicles to be permanently damaged.
Differing delivery methods concerning PRP and the concentration of PRP can influence outcomes as well. Typically, platelet-rich plasma (PRP) for alopecia treatments is injected using small needles or microneedling devices that are used to force the solution to the proper depth for tissue interaction. Since PRP can only be absorbed through the pores of the skin and hair shafts, it is an inexact method of delivery.
The second issue with PRP deals with the variability of platelet concentrations within PRP. Single-spin methods in preparing PRP are inferior to dual-spin methods in preserving CD34+ cells and in the concentration of platelets needed for differentiation, regeneration, angiogenesis, and new cell proliferation to begin. The FDA-approved dual-spin method of harvesting blood platelets yields over six times more than other methods of harvesting platelets.
Other factors affecting successful outcomes are the handling of the PRP and proper diagnosis of the patient’s type of hair loss.
The practical side of using PRP in alopecia treatments is that there are a number of hair follicles that are dormant despite their condition. Platelet-rich plasma has been shown to initiate hair growth for these dormant cells due to the biological nature of the treatment and interaction of stem cells within the hair follicle. Therefore, PRP is beneficial whether used alone or in combination with hair transplantation, medications, red LED light therapy, or another alopecia treatment.