Efficacy and Tolerability of a Topical Gel Containing Milk-Derived miRNA-Enriched Exosomes in Androgenetic Alopecia and Telogen Effluvium: A 12-Week Randomized, Double-Blind, Placebo-Controlled Trial

Androgenetic alopecia (AGA) and chronic telogen effluvium (TE) are common hair loss disorders with substantial psychosocial impact and limited effective topical options beyond minoxidil. MicroRNAs (miRNAs) have emerged as promising modulators of hair follicle cycling via Wnt/β-catenin and related pathways. In this multicenter, randomized, double-blind, placebo-controlled clinical trial, adults aged 18–60 years with AGA, female AGA, or TE were allocated 1:1 to receive a topical gel containing bovine milk-derived exosomes enriched in specific miRNAs (MEV-miRNA gels) or placebo once weekly for 12 weeks. Primary endpoints were changes in anagen hair percentage, anagen/telogen ratio, and hair shaft diameter assessed by digital photo-trichogram at week 8 and week 12 versus baseline; secondary endpoints included patient-reported outcomes, global clinical assessment, and safety/tolerability. Of 40 randomized subjects, 39 (97.5%) completed the study. In the MEV-miRNA gel group, anagen hair percentage increased from 58% at baseline to 70% at week 8 and 78% at week 12, with corresponding improvements in anagen/telogen ratio (from 1.45 to 2.46 and 3.63) and mean hair shaft diameter (from 47.5 µm to 65.3 µm and 70.6 µm; all p < 0.05 vs. baseline and vs. placebo). The placebo did not show significant changes in trichoscopic parameters. At week 12, most MEV-miRNA-treated patients reported stronger hair, reduced shedding, and improved overall hair quality, with high satisfaction rates and no treatment-related serious adverse events. Once-weekly application of a topical gel containing bovine milk-derived microRNA-enriched exosomes significantly improved trichoscopic and patient-reported outcomes in AGA and TE over 12 weeks, with a favorable short-term tolerability profile. These findings support exosome-based microRNA delivery as a novel, non-pharmacologic therapeutic approach for hair loss disorders.