Abstract
Hybrid 755-nm/1064-nm laser systems may improve hair reduction by combining strong melanin absorption with deeper dermal penetration. This study compared a synchronized hybrid dual-wavelength mode with a single 755-nm alexandrite mode. In this prospective, single-blind, split-body controlled trial with alternating allocation, 41 adults underwent three laser sessions at 4-week intervals using one integrated platform. One bilateral subsite was treated with single 755-nm mode and the contralateral subsite with hybrid 755-nm/1064-nm mode. The primary outcome was change in trichoscopic hair thickness from baseline to 20 weeks. Secondary outcomes included hair density, pain, satisfaction, and adverse events. Thirty-six participants completed the per-protocol analysis. Hair thickness decreased significantly with both modes, with a greater reduction after hybrid treatment (between-mode difference, 0.00461 ± 0.00745 mm; 95% CI, 0.00209-0.00713; p = 0.0007), corresponding to an approximately 28% larger relative reduction. Hair density reduction did not differ significantly (p = 0.238). Pain was slightly higher with hybrid treatment at the second session only, but satisfaction was comparable. No device-related adverse events occurred at hybrid-mode sites. The synchronized hybrid 755-nm/1064-nm mode produced superior hair-thickness reduction compared with single 755-nm treatment, with comparable satisfaction and favourable tolerability.