Platelet-Rich Plasma (PRP): Current Applications in Dermatology

Jason Emer, MD


Skin Therapy Letter. 2019;24(5):1-6. 

In This Article

Hair Restoration

PRP has demonstrated significant improvements in hair growth when treating androgenic alopecia (AGA) (Figure 2). PRP growth factors promote hair regrowth by stimulating stem cell differentiation of hair follicles, inducing and prolonging the proliferative anagen phase of hair follicles, as well as activating anti-apoptotic pathways and promoting angiogenesis to increase perifollicular vascularization and the survival of dermal papilla fibroblasts.[2,8–10]

Figure 2A.

Significant increased in hair density and color with six monthly injections of PRP/ACell®, male.

Figure 2B.

Significant increased in hair density and color with six monthly injections of PRP/ACell®, female.

A wide array of studies indicates that PRP is a promising treatment for thinning hair.[2] Both male and female pattern hair loss, as well as alopecia areata, can be improved with PRP. Injections of PRP may be combined with progesterone, dalteparin microparticles, or CD34+ cells. PRP administered with progesterone naturally inhibits 5-alpha reductase, the enzyme that converts testosterone to dihydrotestosterone (DHT). DHT damages hair follicles and is culpable in genetic hair loss. Progesterone inhibits 5-alpha reductase and thus DHT, which allows hair growth to recover. PRP with dalteparin induced significant increases in hair diameter and proliferation of collagen fibers and fibroblasts, along with thickened epithelium and hair follicles due to increased angiogenesis.[11] Using CD34+ cells with PRP showed significant improvement in hair thickness and overall presentation.[12]

While some studies reveal minimal improvement in hair restoration, it is hypothesized that inadequate treatment protocols have been used. Studies using an insufficient number of treatments lacked substantial improvements.[2] Multiple continued treatments with PRP is necessary for significant aesthetic improvement of increased hair density. It is thought that three injections per year is the minimum frequency in order to observe any clinically beneficial result. In clinical practice, most physicians commence with a series of monthly injections until improvement is seen, then continuing with maintenance therapies every 2 to 3 months indefinitely. More research is needed nevertheless to determine proper frequency, dosing, and maintenance. Furthermore, combining PRP injections with other hair restoration treatments, such as finasteride (male patients), minoxidil, low-level light therapy, and spironolactone (female patients), may enhance the overall efficacy. PRP injections may also improve the outcome of hair transplantation and may soon be part of the pre-treatment and post-treatment maintenance protocols. In clinical practice, the author (JE) has found substantial improvement with the use of ACell® (naturally-occurring urinary bladder matrix epithelial basement membrane; MicroMatrix®) and/or human exosomes (placental mesenchymal stem cell and amniotic fluid derived; Kimera Labs, Inc.) combined with PRP in patients with less than substantial improvement with PRP injections alone. Combined with hair transplantation, injectable regenerative therapies have shown improved outcomes in the author's experience.