Red light therapy has systemic, not just local, effects. In one study, illuminating a small patch on participants' backs with red light before a glucose challenge reduced their peak blood sugar spike by over 20%. This suggests mitochondria communicate body-wide to create a systemic metabolic response.

The unbalanced, short-wavelength-heavy spectrum of common LED lights, which lacks counteracting long-wavelength red light, may cause systemic mitochondrial dysfunction. Some scientists believe this is a major public health issue with a potential impact comparable to that of asbestos.

Incandescent and halogen bulbs provide a full, sun-like spectrum of light that supports mitochondrial health, unlike spectrum-limited LEDs. Using a dimmable halogen lamp, even at low brightness, provides ample beneficial infrared energy. This simple, low-cost switch can counteract the negative effects of modern indoor lighting.

Red light therapy is a powerful preventative and early-stage intervention tool, but it cannot reverse advanced disease. Clinical trials showed it failed to help patients with late-stage macular degeneration or severe rheumatoid arthritis, yet significantly helped those with milder conditions, emphasizing the need for early application.

Experiments show that long-wavelength red and infrared light can penetrate the human skull, which it passes through more easily than deoxygenated blood in veins. This property is already being used by biomedical engineers to non-invasively monitor mitochondrial function in the brains of newborns who have suffered a stroke.

All plant matter naturally reflects infrared light. Placing plants in an office or home, especially where they can catch sunlight, increases the ambient levels of health-promoting long-wavelength light. Architects are beginning to incorporate this principle into building design to create healthier indoor environments.

The benefits of red light therapy are highly time-dependent. Mitochondria are most receptive and primed for ATP production in the morning, making treatments before 11 AM significantly more effective. Afternoon sessions have little to no effect as mitochondria shift to other maintenance tasks.

Unlike treatments like microneedling that wound skin to trigger a healing and collagen-building response, red light therapy operates differently. It stimulates mitochondria to increase cellular energy (ATP). This energizes cells responsible for building collagen without causing any initial damage, offering a less invasive anti-aging pathway.

Mice living under standard LED lighting develop significant health problems, including fatty livers, smaller kidneys and hearts, unbalanced blood glucose, and anxiety-like behaviors. This suggests the unbalanced light spectrum in modern indoor environments may have profound, detrimental systemic effects on mammalian health.