Red light therapy: what 204 trials add up to

What they did

Photobiomodulation is the proper name for red and near-infrared light therapy. The authors pulled together 15 meta-analyses covering 204 randomized trials and more than 9,000 people, across 35 health outcomes and 15 conditions, then graded how trustworthy each pooled result was.

What they found

Light therapy showed a significant effect for 12 of the 35 outcomes. The results with moderate certainty were pain in burning mouth syndrome, disability in knee osteoarthritis, fatigue in fibromyalgia, hair density in pattern hair loss, and cognitive function. Most other outcomes came out as low or very low certainty, because studies disagreed with each other or the small ones looked too good.

The Luxe read

This is the honest state of red light: not a scam, not a miracle. The strongest signals are in fatigue, joint disability, hair and cognition. Skin rejuvenation, the thing most panels are sold for, is not on the moderate-certainty list here. The authors also point out that protocols vary wildly, which is why two panels with the same LEDs can produce different studies.

Questions worth asking

• Which wavelength, dose and distance did the positive trials use, and does my device match?
• Am I buying it for one of the outcomes with evidence, or for one with vibes?
• What would I expect to see, and by when, so I know whether it is doing anything?