Scott Nelson's core argument is simple but easy to miss: we're not just getting too much lightâwe're getting the wrong kind. That 93% indoors statistic isn't a curiosity. It's a description of a species that evolved under a full-spectrum light environment now living almost entirely under narrow-spectrum artificial light. Blue and white light all day, then more blue and white light from screens in the evening. The red and near-infrared wavelengths that dominated sunrise and sunset for most of human history? Largely absent.
Red light therapy is essentially supplementation for a deficiency most of us don't know we have.
The photobiomodulation research is more robust than most people realize. The mechanism is specific: red and near-infrared wavelengths in the 630-850 nanometer range are absorbed by cytochrome c oxidase, a protein in the mitochondrial electron transport chain. This absorption upregulates ATP productionâcellular energy output. From there, effects cascade: reduced oxidative stress, increased collagen synthesis, modulated inflammation.
Where the evidence is strongest: wound healing, skin rejuvenation, localized pain relief, and reducing inflammation markers. Where it's more variable: the athletic performance claims depend heavily on timing, duration, and wavelength specificity. Not all red light devices are equal. Consumer devices often underdeliver on the irradiance levels used in clinical studies.
Nelson mentions that red light helps the body produce more melatonin. This is where I'd point people toward the circadian biology research that runs through our entire knowledge base. Evening red light exposure doesn't suppress melatonin the way blue light does. It may actually support the pineal gland's natural melatonin ramp-up. This creates a practical pairing: red light therapy in the evening as both a recovery tool and a sleep preparation ritual.
It connects directly to the temperature research too. Your core body temperature drops naturally in the evening to signal sleep onset. Sauna use in the evening works partly through this same mechanismâyou heat up, then cool down, amplifying the drop. Red light doesn't produce that thermal cascade, but it complements the circadian wind-down through a different pathway. Two tools, different mechanisms, reinforcing the same biological signal.
Morning or evening use, 10-20 minutes, at a distance of 6-12 inches from the device. Morning sessions have energizing effects through ATP upregulation. Evening sessions support recovery and sleep. Don't use it at midday and expect circadian benefitsâtiming is the difference between a useful tool and an expensive lamp.
If you're already doing sauna or cold exposure, think about where red light fits in the sequence. Post-cold, when circulation is returning to the surface, is a particularly interesting window for photobiomodulation. The mechanisms stack rather than cancel.
We talk constantly about hormesisâthe principle that controlled stressors build resilience. Heat. Cold. Exercise. Fasting. Red light works differently. It's not primarily a stressor. It's a signal that says "optimize." Same mitochondria, different message. Understanding that distinction changes how you think about where it fits in a recovery protocol. You don't need to earn it. You just need to be consistent with it.