Platelet-rich plasma therapy for hair loss is a three-step medical treatment in which a person’s blood is drawn, processed, and then injected into the scalp. PRP injections trigger natural hair growth and maintain it by increasing blood supply to the hair follicle and increasing the thickness of the hair shaft. PRP is a form of regenerative medicine that can harness those abilities and amplify the natural growth factors your body uses to heal and stimulate the hair follicle. Plasma is the liquid portion of whole blood. It is composed of largely of water and proteins, and it provides a medium for red blood cells, white blood cells and platelets to circulate through the body.