Are PRP (Platelet-Rich Plasma) 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 are thought to stimulate tissue repair and hair follicles. How long any effect lasts is uncertain. PRP for hair loss is off-label. The devices used to prepare PRP are FDA-cleared for processing blood, but no PRP product is FDA-approved to treat hair loss (Gupta & Carviel, 2017; Paichitrojjana & Paichitrojjana, 2022). Reported side effects are usually mild and temporary: pain during the injections, mild headache, itching, redness and swelling of the treated area (Paichitrojjana & Paichitrojjana, 2022). The same review lists platelet disorders, a very low platelet count and infection at the injection site as reasons not to have PRP. Anyone taking blood-thinning (anticoagulant or antiplatelet) medicines or anti-inflammatory painkillers should tell the clinician before treatment, because these affect bleeding and platelet function; never stop a prescribed blood thinner without advice from the prescribing doctor.

Temporary Boost Rather Than Permanent Solution

There is no evidence that PRP provides a permanent solution for hair loss. Pattern hair loss is progressive and PRP is not thought to change its cause, so hair loss would be expected to continue after treatment stops; few trials have followed patients long enough to measure this. The growth factors in PRP, such as platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and transforming growth factor-beta (TGF-β), are thought to enhance the anagen phase of hair growth only for a time.** They are not thought to alter the underlying hormonal sensitivity that drives hair follicle miniaturization in androgenetic alopecia.**

In 2015, Gentile and colleagues in Italy ran a randomized, evaluator-blinded, placebo-controlled half-head trial in men with pattern hair loss (23 enrolled, 3 excluded). PRP was injected on one half of the scalp and placebo on the other, in three sessions 30 days apart. After the third session, the authors reported a mean increase of 33.6 hairs in the target area and 45.9 hairs per cm² in total hair density compared with baseline; the abstract does not give the difference from the placebo side. Four patients had progressive hair loss again after 12 months and were re-treated (Gentile et al., 2015). This is one of the few trials that followed patients beyond one year, and it was small.

Meta-analyses of small trials report modest increases in hair density over 3 to 6 months; long-term data are scarce (Zhang et al., 2023). Reviews also raise concerns about small sample sizes, methodological differences, and short-term follow-ups across studies, so results should be interpreted with caution.

Critical Perspective on Mechanism and Expectations

PRP’s proposed effect is the activation of dormant hair follicles through growth factors, which are thought to enhance vascularization and cellular activity in the scalp for a time. 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.

Small trials have reported improvements in hair density, but there is no evidence that these effects are permanent. Clinics usually offer maintenance sessions, and pattern hair loss is expected to keep progressing if the therapy is stopped. 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

Gentile, P., Garcovich, S., Bielli, A., Scioli, M. G., Orlandi, A., & Cervelli, V. (2015). The effect of platelet-rich plasma in hair regrowth: A randomized placebo-controlled trial. Stem Cells Translational Medicine, 4(11), 1317–1323. https://pubmed.ncbi.nlm.nih.gov/26400925/

Gupta, A. K., & Carviel, J. L. (2017). Meta-analysis of efficacy of platelet-rich plasma therapy for androgenetic alopecia. Journal of Dermatological Treatment, 28(1), 55–58. https://pubmed.ncbi.nlm.nih.gov/27152474/

Paichitrojjana, A., & Paichitrojjana, A. (2022). Platelet rich plasma and its use in hair regrowth: A review. Drug Design, Development and Therapy, 16, 635–645. https://pubmed.ncbi.nlm.nih.gov/35300222/

Zhang, X., Ji, Y., Zhou, M., et al. (2023). Platelet-rich plasma for androgenetic alopecia: A systematic review and meta-analysis of randomized controlled trials. Journal of Cutaneous Medicine and Surgery, 27(5), 504–508. https://pubmed.ncbi.nlm.nih.gov/37533146/