Fractional Laser Therapy for Androgenetic Alopecia: Mechanisms, Clinical Evidence, and Practical Implementation.

Fractional laser therapy has emerged as a mechanistically targeted, device-based option for androgenetic alopecia (AGA), leveraging controlled dermal injury, wound-healing cascades, and laser-assisted drug delivery to promote hair follicle regeneration. Non-ablative erbium:glass systems at 1550 to 1565 nm and ablative platforms at 2940 and 10,600 nm activate hair follicle stem cells, upregulate Wnt/β-catenin signaling, enhance perifollicular vascularity, and modulate chronic perifollicular inflammation, translating into clinically meaningful gains in hair density and shaft diameter across male and female AGA. Head-to-head data show 1565 nm non-ablative fractional laser achieving superior short-term improvements in hair density and terminal hair counts.