Platelet-rich plasma in androgenetic alopecia – hype or hope?

Platelet-rich plasma (PRP) might present a promising treatment option in androgenetic alopecia, but hair restoration using PRP is still at its infancy: more scientific data is urgently needed.

PRP is defined as a portion of the plasma fraction of autologous blood with a platelet concentration above baseline. However, as Prof. Ronda S. Farah (University of Minnesota, MN, USA) emphasised, its use in androgenetic alopecia is questioned: the first problem is that no standardised protocol for preparing PRP exists. PRP probably acts by growth factors that stimulate and inhibit hair growth (see Figure). Platelets can be activated before application of PRP, but whether this is necessary is a matter of debate. In addition, there is no clear PRP regimen; most users recommend monthly injections with a possible booster about 6 months later.

Figure: Activated platelets release several growth factors that may be responsible for the treatment effect of platelet-enriched plasma [1]



SG, sebaceous gland; B, bulge region; HS, hair shaft; DP, dermal papilla; PDGF, platelet-derived growth factor; EGF, epidermal growth factor; FGF, fibroblast growth factor; VEGF, vascular endothelial growth factor; IGF, insulin-like growth factor; TGFβ; transforming growth factor β.

The side effects of PRP include pain at the injection site. “Massage the area or distract the patient to alleviate pain,” Prof. Farah recommended. She applies PRP specifically to the thinning regions.

In a real-world study, PRP combined with 5% minoxidil led to a positive response in 71% of patients at 2 months: the PRP combination demonstrated a significant increase in hair density. In a randomised controlled split-scalp study including 35 patients with androgenetic alopecia, one side of the scalp was treated with PRP and the other with a saline solution as placebo. Hair density increased on both sides, but this difference failed to reach statistical significance [3]. In a systematic review, 84% of studies demonstrated a positive effect, but only 50% had objective measurements [4]. The authors concluded that PRP is efficient and well tolerated. Simultaneous use of PRP and minoxidil demonstrated the highest rate of improvement and satisfaction [4]. PRP proved also effective in women with androgenetic alopecia [5].

Prof. Farah stressed that additional research with standardised PRP protocols is needed. There are several questions concerning the ideal volume or platelet concentration to inject. “One should disclose to patients that it is an off-label treatment,” Prof. Farah recommended.

1. Farah R. Evidence based summary of photobiomodulation and platelet rich plasma. Session S0017, AAD VMX 2021, 23-25 April.
2. Ho A, et al. J Am Acad Dermatol 2020;82(2):478-9.
3. Shapiro J, et al. J Am Acad Dermatol 2020;83(5):1298-1303.
4. Roohaninasab M, et al. Dermatol Ther 2021; e-pub 09 January 2021.
5. Dubin DP, et al. J Am Acad Dermatol 2020;83:1294-7.

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Posted on 7 June 202117 May 2024