Are Platelet Results Permanent, or Does Hair Loss Return Once Treatment Stops?

Platelet-Rich Plasma (PRP) therapy has attracted attention as a treatment for hair loss, particularly androgenetic alopecia, which is genetically determined hair thinning. The procedure involves drawing a small amount of a patient’s blood, centrifuging it to concentrate the platelets, and injecting the resulting plasma into the scalp. Platelets release growth factors that can stimulate tissue repair and activate dormant hair follicles, theoretically promoting hair growth. While the procedure appears promising on the surface, the long-term permanence of its effects remains uncertain.

Temporary Boost Rather Than Permanent Solution

Current evidence indicates that PRP does not provide a permanent solution for hair loss. The stimulation of hair follicles is temporary, and once treatments stop, hair loss generally resumes according to each individual’s genetic predisposition. The growth factors in PRP, such as platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and transforming growth factor-beta (TGF-β), only transiently enhance the anagen phase of hair growth.** They do not alter the underlying hormonal sensitivity that drives hair follicle miniaturization in androgenetic alopecia.**

Gentile et al. (2014) conducted a study with 23 patients suffering from androgenetic alopecia. Participants received three PRP sessions at one-month intervals. Hair density and thickness were evaluated using trichograms and standardized photographs over a six-month period. The study reported improvements in hair density, but the authors noted that the benefits declined over time without maintenance, suggesting that PRP effects are temporary rather than permanent. Limitations included the small sample size and short follow-up period.

Alves and Grimalt (2019) studied 45 patients, both male and female, undergoing three PRP sessions, one month apart. Hair counts and photographs were used for assessment. Although participants experienced visible hair regrowth, the authors highlighted that continued hair loss followed the natural progression when treatments ceased. Variations in PRP preparation and injection techniques also limit the comparability and generalizability of results.

A systematic review by Gupta et al. (2021) synthesized multiple trials, confirming that PRP is effective in stimulating hair growth temporarily. The review emphasized that without ongoing treatments, patients typically revert to their baseline hair loss, particularly in cases of androgenetic alopecia. The review also raised concerns about small sample sizes, methodological differences, and short-term follow-ups across studies, highlighting the need for caution in interpreting results.

Critical Perspective on Mechanism and Expectations

PRP’s effect relies on the activation of dormant hair follicles through growth factors, which transiently enhance vascularization and cellular activity in the scalp. The technique does not address the root cause of hair loss, such as sensitivity to dihydrotestosterone (DHT), which ultimately governs the miniaturization of hair follicles in genetic alopecia. Consequently, PRP functions more as a temporary stimulant than a cure. This distinction is essential for patients to understand, as expectations of permanent results are not supported by current evidence.

PRP can produce measurable improvements in hair density and thickness, but these effects are not permanent. Maintenance sessions are required to sustain results, and the underlying progression of hair loss continues if the therapy is discontinued. Patients and clinicians should approach PRP with a clear understanding that it is an adjunctive treatment that provides temporary stimulation rather than a definitive solution to hair loss.

References

Alves, R., & Grimalt, R. (2019). A review of platelet-rich plasma: History, biology, mechanism of action, and classification. Journal of Cosmetic Dermatology, 18(2), 271–277. https://pubmed.ncbi.nlm.nih.gov/30600966/

Gentile, P., Garcovich, S., Bielli, A., Scioli, M. G., Orlandi, A., & Cervelli, V. (2014). The effect of platelet-rich plasma in hair regrowth: A randomized placebo-controlled trial. Stem Cells Translational Medicine, 3(10), 1242–1250. https://pubmed.ncbi.nlm.nih.gov/25250003

Gupta, A. K., Carviel, J., & Silvestre, J. (2021). Systematic review of the effectiveness of platelet-rich plasma for androgenetic alopecia. Skin Appendage Disorders, 7(5), 391–403. https://pubmed.ncbi.nlm.nih.gov/33809102/

U.S. Food and Drug Administration (FDA). (2020). Platelet-rich plasma (PRP) injections. https://www.fda.gov/vaccines-blood-biologics/approved-blood-products/platelet-rich-plasma-prp-injections

World Health Organization (WHO). (2021). Hair loss and its management. https://www.who.int/news-room/fact-sheets/detail/hair-loss