Exosomes in trichology: A literature review

Exosomes, nano-sized extracellular vesicles derived from various cell types, have emerged as a promising therapeutic modality in trichology. These vesicles deliver bioactive molecules, such as growth factors, cytokines, and microRNAs, that regulate key cellular processes, including proliferation, differentiation, and signaling, which are critical for hair follicle regeneration.

This review synthesizes findings from preclinical and clinical studies published on the applications of exosomes for treating hair loss conditions such as androgenetic alopecia (AGA), alopecia areata (AA), and chemotherapy-induced alopecia (CIA).

A comprehensive literature search was conducted using databases including MEDLINE, PubMed and Ovid databases for relevant studies published on clinical trials, diagnosis and treatment. Some papers were further reviewed using a double-blinding approach, sample size, control usage, randomization usage and objective endpoint measurements. All studies were classified according to the Oxford Center for evidence-based medicine evidence hierarchy.

Preclinical studies demonstrate that exosomes derived from mesenchymal stem cells (MSCs), adipose stem cells (ASCs), dermal papilla cells (DPCs) and plant sources enhance dermal papilla cell (DPC) proliferation, activate signaling pathways such as Wnt/β-catenin, VEGF, and PI3K/AKT, and promote the transition of hair follicles from the telogen to anagen phase. Clinical data, although limited, show promising results, with improvements in hair density, thickness, and follicular health. Systematic reviews and case series have highlighted the favorable safety profile of exosome-based therapies, with minimal adverse effects reported.

Exosome therapy is a promising, minimally invasive approach for AGA, AA, and CIA, supported by robust preclinical biology but preliminary and heterogeneous clinical data. Progress to routine practice will require adequately powered, multicenter randomized trials with standardized outcomes, along with harmonized manufacturing and regulatory frameworks (GMP-compliant production, batch-level quality control) to ensure reproducibility and safety.