PRP: A New Treatment for Hair Loss -

Sheila Krishna, M.D.

Platelet rich plasma (PRP) is an exciting new technique in the field of hair restoration. The principle of PRP has been studied for over 20 years in various medical fields and has recently been studied for dermatological applications such as skin rejuvenation and hair growth. PRP represents a novel method for induction of hair growth and complements existing treatments for hair loss.

PRP is defined by the FDA as a biological product that contains the plasma fraction of blood with a high platelet concentration. In addition to platelets, PRP contains a variety of blood products, and the exact concentration depends on the technique by which is is prepared.

The term PRP was first used in the 1970s by hematologists in order to describe the plasma extract of whole blood which contained platelets. Platelets contain several important molecules that contribute to healing and homeostasis, which is the body’s intrinsic ability to regenerate and balance itself.

In the 1980s, with increasing recognition of the complexity of platelets and their growth factors, PRP began to be used in the field of orthopedic and sports medicine for its anti-inflammatory and healing properties. PRP has enjoyed its greatest use in the treatment of hip and knee osteoarthritis, along with various orthopedic injuries. PRP is frequently used for treatment of knee and hip arthritis via injection or bathing of a surgical site during a procedure.

In dermatology, PRP was first used for its wound healing properties, specifically for non-healing ulcers, scar revision, and tissue regeneration. Because wounds tend to have high levels of inflammatory markers, PRP was used as an anti-inflammatory product that would promote healing, improve cellular regeneration and blood flow, and restore homeostasis. These properties were then studied for their role in skin rejuvenation, where it was shown that PRP can stimulate collagen and fibroblast growth, along with promoting soft tissue growth.

In addition to these uses, PRP was also considered by dermatologists for the treatment of hair loss starting in the early 2000s. Dermatologists treat many types of hair loss, which are generally divided into scarring and non-scarring . Scarring hair loss typically includes autoimmune hair loss, such as that seen in lupus or other inflammatory disorders, which leaves the follicle scarred and generally unable to grow hair. Non-scarring hair loss includes male and female pattern hair loss, alopecia areata, as well as other types.

PRP has been most studied for its role in male pattern hair loss and female pattern hair loss. It has formally been evaluated in the treatment of male pattern hair loss.

Male pattern hair loss occurs due to alterations in the hormonal and inflammatory environment of the hair follicle and is typically driven by testosterone and its derivative, dihydrotestosterone (DHT). In normal hair follicles, testosterone predominates and preserves follicle size, shape, and density. Due to a variety of factors, including genetic influences, testosterone can be increasingly converted to DHT. DHT has a direct effect on hair follicles, causing shrinkage and degeneration of the follicle, which results in predictable patterns of hair loss seen in men and women.

Current treatments for male pattern hair loss typically focus on the changes that testosterone and DHT cause in the hair follicle, along with general growth of the follicle. Minoxidil (Rogaine) is currently approved for the treatment of male and female pattern hair loss, and it is believed that it works by increasing the length of time that hair grows and by increasing blood flow to the follicles.

Finasteride (Propecia) is approved for the treatment of male pattern hair loss and decreases concentrations of DHT by inhibiting the enzyme that converts testosterone to DHT. Finasteride is very effective for male pattern hair loss, however, side effects of this medication include decreased libido, erectile dysfunction, and changes in prostate specific antigen levels. For these reasons, patients and physicians have sought alternate treatments for pattern hair loss. A common alternate treatment has been hair transplantation, which has undergone various refinements over time to be minimally invasive and effective, with natural appearing results. However, hair transplant is laborious and expensive.

PRP was introduced as an alternative treatment for male pattern hair loss, and as an adjunct to traditional treatments such as Minoxidil and Finasteride.

PRP contains several growth factors that affect hair follicles, including platelet derived growth factor, vascular growth factor, and several others. These proteins regulate how cells move and grow in the skin and hair follicles, and they also interact with hair follicle stem cells. When these proteins act on the hair follicle stem cells, they lead to proliferation and growth of the follicle and also increase blood flow to and oxygenation of the hair follicle, which further potentiates growth.

PRP is obtained by collecting a peripheral blood sample from a vein, as is done in any blood draw. The sample is then placed in a centrifuge, a machine which spins at a high velocity to separate blood components. This sample is subsequently subjected to further centrifugations in order to concentrate platelets, fibrin, and other components as desired. This concentrated extract is termed platelet rich plasma, or PRP.

Once PRP is extracted from the blood and concentrated, it is then injected into the scalp in the areas of thinning hair. The treatment areas are usually numbed with a topical anesthetic prior to PRP injection. The injections are placed in the dermis, at the level of the hair follicle, and are regularly spaced over the areas of the scalp that do not have hair. The three steps of a PRP treatment- blood draw, PRP concentration, and PRP injection- can be done in a doctor’s office and usually take about an hour.

A large review article evaluated twelve studies performed between 2007-2011. These twelve studies, which together included 300 participants, were reviewed to evaluate the role of PRP in male pattern hair loss. Ten of these studies showed that PRP improved hair growth. However, two studies concluded that PRP was ineffective based on hair counts, but in these studies, the subjects were only given 2 treatments and outcomes were not assessed using microscopic techniques. Participants in these two studies did report improved hair thickness and less hair shedding.

The majority of studies in this review showed improvement in hair loss and better hair growth, along with increased hair counts. Overall, hair counts and thickness increased 10-30%. Further, results were improved when PRP was utilized along with other treatments, such as minoxidil and finasteride, with a slightly better improvement using minoxidil over finasteride. With respect to treatment intervals, it was found that the best results were obtained when PRP was performed on a monthly basis for at least 3 months.

Further studies have since been performed to refine a protocol for PRP and confirm its effectiveness. A single center, blinded, randomized study performed in 2018 utilized 2 two groups of subjects: the first group received injections at months 1,2,3, and 6 and the second group at months 1 and 3. Group 1 had a 29% increase in hair counts and 30% increase in hair density at month 6, while group 2 had only a 7% increase in hair counts and 20% increase in hair density at month 6. This suggests that PRP be performed at monthly intervals for 3 months followed by an additional treatment at 6 months. In this study, patient satisfaction was also evaluated, and the procedure was found to be minimally painful and well tolerated by all patients, with 82% stating they were satisfied or highly satisfied.

Taken together, there is strong evidence for the safety, tolerability and efficacy of PRP for male pattern hair loss. While there are small studies on it’s role for female pattern hair loss, and certain centers are performing PRP for female pattern hair loss, larger studies need to be performed. Further, the role of PRP for other types of hair loss, such as autoimmune hair loss, remains to be elucidated.

PRP offers an excellent complement to traditional treatments for male pattern hair loss and can be safely performed in an office setting with minimal downtime and good efficacy.

Side effects of PRP include pain, swelling, and redness, along with possible infection or blood product contamination. Meticulous handling of the blood product and measures to avoid contamination, along with appropriate technique, can mitigate these risks. PRP should be performed by an experienced and appropriately trained physician or closely supervised provider who can assess the need for PRP and provide a safe, comfortable, and effective treatment experience.

PRP represents a novel, new technique for hair rejuvenation and restoration.

References

Alves, R. et al. Platelet-Rich Plasma in Combination With 5% Minoxidil Topical Solution and 1 mg Oral Finasteride for the Treatment of Androgenetic Alopecia: A Randomized Placebo-Controlled, Double-Blind, Half-Head Study. Dermatol Surg. 2018 Jan;44(1):126-130.

Alves, R et al. Randomized Placebo-Controlled, Double-Blind, Half-Head Study to Assess the Efficacy of Platelet-Rich Plasma on the Treatment of Androgenetic Alopecia. Dermatol Surg. 2016 Apr;42(4):491-7.

Badran KW, Sand JP. Platelet-Rich Plasma for Hair Loss: Review of Methods and Results. Facial Plast Surg Clin North Am. 2018 Nov;26(4):469-485.

Cervantes, J. et al. Effectiveness of Platelet-Rich Plasma for Androgenetic Alopecia: A Review of the Literature. Skin Appendage Disord. 2018 Jan;4(1):1-11.

Hausauer, AK et al. Evaluating the Efficacy of Different Platelet-Rich Plasma Regimens for Management of Androgenetic Alopecia: A Single-Center, Blinded, Randomized Clinical Trial. Dermatol Surg. 2018 Sep;44(9):1191-1200.

Rodrigues, B. Treatment of male pattern alopecia with platelet-rich plasma: A double-blind controlled study with analysis of platelet number and growth factor levels. JAAD Volume 80, 694 – 700.

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