Platelet Rich Plasma (PRP)
What is PRP?
Platelet rich plasma (PRP) is concentrated blood plasma which contains approximately three to five times the number of platelets found in normal circulating blood. In addition, it contains platelet derived growth factor (PDGF), vascular endothelial growth factor (VEGF), transforming growth factor (TGF) and other bioactive proteins that aid in wound healing and possibly hair growth.
Human blood is comprised primarily of red blood cells (RBC), as well as white blood cells (WBC), platelets, and plasma. By initiating the first step of coagulation, platelets are the key to the body’s ability to heal wounds.
It is thought that by increasing the platelet count in a wounded area, the body’s healing to that area would be accelerated – explaining the use of PRP (platelet rich plasma) in wound healing. Its possible effects on promoting hair growth would make it potentially useful in both hair transplantation and the medical treatment of hair loss.
How is PRP Prepared and Used?
The Platelet Rich Plasma (PRP) commonly used in hair restoration is “autologous” meaning that it is derived from the patient’s own blood. To obtain PRP, a patient’s blood is spun in a centrifuge to separate the solid from liquid components and platelet activators, such as thrombin, calcium chloride and sometimes collagen, are added. The separated “solid” portion of the blood is PRP (platelet rich plasma).
There are commercially available kits for PRP treatment. These include: Cydomedix, Emcyte Pure PRP, Angel system, and Harvest system. PRP is sometimes combined with A-Cell.
The PRP is then placed into a syringe and reintroduced into the treatment site i.e., either the surgical site or an area of hair loss. PRP be can sprayed onto a recipient area during and after a hair transplant, laid into the donor incision, or injected directly into a balding scalp. Prior to injecting PRP, doctors often create a ring-block of local anesthesia with 1% lidocaine.
When used to stimulate hair growth most doctors schedule injections at intervals of 3 to 9 months. Some improvement (in reversing miniaturization) can be expected in the first 2-6 months. The treatments must be continued periodically to maintain any improvement.
Mechanism of Action in Hair Transplants
Hair follicles survive through the absorption of oxygen from surrounding tissue. It is conjectured that the introduction of platelets and white blood cells through platelet rich plasma (PRP) would amplify the body’s naturally occurring wound healing mechanism. It is also proposed that PRP can actually stimulate the stem cells (dermal papilla) of the newly transplanted hair follicles.
For the medical treatment of hair loss, some practitioners claim that PRP can be used to stimulate the growth of follicles, thereby reversing hair miniaturization seen in androgenetic alopecia, and even to prevent hair loss.
What are the Indications for PRP?
PRP is used in many areas of medicine, including the acceleration of healing of tendon injuries, the treatment of osteoarthritis, in some aspects of dental work (i.e. jaw reconstruction), and in cardiovascular medicine. The concentrated form of plasma has been shown to accelerate wound healing and tissue repair and, thus, could potentially benefit hair restoration procedures.
In hair transplantation, PRP can be injected into or sprayed on the recipient site area to, theoretically, stimulate the healing of the transplanted grafts and into the donor area to facilitate healing of the donor incision and potentially minimize scar formation.
In the medical treatment of male and female pattern baldness (androgenetic alopecia), PRP can be injected into the balding scalp to potentially stimulate thin (miniaturized) hair to grow into thicker (terminal) hairs. Patients with thinning, but not totally bald areas, would be the best candidates.
While there is much conjecture as to the benefits of using PRP during hair transplantation and its use in the medical treatment of hair loss, there is currently scant scientific evidence to support these theories. The few reported studies have been with a small number of patients and for a limited period of time. As of this date, there have been no large randomized, placebo controlled, clinical studies to prove that PRP can positively affect hair growth on the long-term.
- Miao, Y., et al. Promotional effect of PRP on hair follicle reconstitution in vivo. Derm Surg. 2013; 39:1869-1876.
- Greco, J., and R. Brandt. Preliminary experience and extended applications for the use of autologous platelet rich plasma in hair transplantation surgery. Hair Transplant Forum Int’l. 2007; 17:131-132.
- Greco, J., and R. Brandt. The effects of autologous platelet rich plasma and various growth factors on non-transplanted miniaturized hair. Hair Transplant Forum Int’l. 2009; 19:49-50.