Red light therapy is vasty undervalued among the techie longevity crowd I know when compared to supplements, perhaps because of the large initial cost and lower portability of systems.
The evidence seems stronger than for most supplements people take, for everything from hair loss to collagen production to soften tissue repair to brain function.
Red light has a negligible effect on hair loss compared to Rogaine (minoxidil), after reading many papers about this. Not sure about the other claims, but they also seem unlikely.
I thought they were overpriced until I looked into building one myself. The heat sinks were going to be really expensive. The LEDs and lenses weren't cheap either.
The evidence seems stronger than for most supplements people take, for everything from hair loss to collagen production to soften tissue repair to brain function.