- Daily red‑light therapy modestly increased hair density.
WIRED tested four consumer devices – the CapillusPro, iRestore Laser, Theradome PRO, and NutraStim – on a group of 12 volunteers (ages 28‑55) with mild to moderate thinning. Each participant used the assigned device every day for 16 weeks, following the manufacturers’ recommended session length (10‑20 minutes). Hair density was measured with a handheld trichometer on a 1 cm² patch of the crown before and after the trial. Across all devices the average gain was 8 % (roughly 12 hairs per cm²), with the CapillusPro showing the highest lift at 11 %.
The results matter because they provide the first head‑to‑head, protocol‑consistent data on consumer‑grade red‑light kits. Earlier claims relied on small case studies or manufacturer‑sponsored trials; WIRED’s independent test suggests the technology can deliver measurable change, but the gains are modest and require strict daily use.
Even with a controlled trial, the improvement is far from a miracle cure, and the effort‑cost ratio remains steep for most users.