Exosome-Based Therapies for Alopecia Areata: A Systematic Review of Clinical and Experimental Evidence

This systematic review evaluates the potential of exosome-based therapies for treating alopecia areata (AA), an autoimmune condition with limited treatment options. The review included 40 studies, comprising clinical, preclinical, in vivo, and in vitro research. Clinical studies reported hair density increases of 9–31 hairs per cm², while experimental studies showed hair coverage improvements of 50–99%. The therapies demonstrated activation of the Wnt/β-catenin pathway, enhanced dermal papilla and hair follicle stem cell function, and anti-inflammatory effects. Safety profiles were favorable, with only mild, transient local reactions reported. Despite promising results, the review highlights the need for robust randomized controlled trials and standardization of exosome sources, doses, and delivery methods before clinical application.