Red Light Therapy Glossary

PBM works primarily through photon absorption by cytochrome c oxidase in mitochondria, enhancing ATP production and modulating reactive oxygen species.

LLLT specifically referred to low-power laser applications, while PBM encompasses both laser and LED sources.

Higher irradiance means shorter treatment times for the same dose. Most consumer devices range from 30-200 mW/cm² at the recommended distance.

Fluence = Irradiance (W/cm²) × Time (seconds). The therapeutic range for most conditions is 3-50 J/cm².

Absorption peaks near 660nm (red) and 810-830nm (NIR). When photons are absorbed, nitric oxide is displaced from the enzyme, allowing more efficient electron transport.

Increased ATP drives cellular repair, proliferation, and anti-inflammatory responses — the downstream therapeutic effects of PBM.

Mitochondrial dysfunction is implicated in many conditions PBM treats. Light absorption by mitochondrial chromophores restores function.

Below ~3 J/cm² may be sub-therapeutic. 3-50 J/cm² is generally therapeutic. Above 100 J/cm² can inhibit cellular function. More is not always better.

This curve explains why optimal dosing is critical — too little light has no effect, too much can be counterproductive.

Red light (630-670nm) penetrates 5-10mm. Near-infrared (810-850nm) penetrates 30-50mm. Different wavelengths target different therapeutic effects.

NIR reaches deep tissues including joints, muscles, and even brain tissue through the skull. Used for pain, neurological, and deep tissue applications.

Red light is absorbed by skin, hair follicles, and superficial tissue. Used for skin rejuvenation, acne, wound healing, and hair growth.

Below 600nm, light is largely absorbed by hemoglobin and melanin. Above 1100nm, water absorption dominates. The 'optical window' allows therapeutic penetration.

LEDs are non-coherent (unlike lasers), less expensive, and cover larger treatment areas. Modern research shows comparable therapeutic outcomes to lasers for most applications.

Class 3B and 4 lasers are used in clinical settings. Consumer devices almost exclusively use LEDs for safety and cost reasons.

Most red light therapy devices are FDA 'registered' (manufacturer self-lists), not 'cleared' or 'approved.' Only some laser caps for hair loss have 510(k) clearance.

WALT guidelines provide specific wavelength, dose, and frequency recommendations. They are considered the gold standard for clinical PBM protocols.

The PBM Foundation supports clinical research and provides resources for healthcare professionals and patients.

Types I and III collagen are primarily stimulated by red light therapy. This drives skin rejuvenation, wound healing, and anti-aging effects.

Red light increases fibroblast proliferation and collagen synthesis, contributing to skin rejuvenation and wound healing.

Increased microcirculation enhances nutrient delivery and waste removal, supporting tissue repair and reducing inflammation.

EMF from LED panels is non-ionizing and at levels generally considered safe. Some brands specifically design for low-EMF output.

Quality devices use flicker-free drivers. Cheap devices may have visible flicker due to poor power supply design.

The RedLightOS app tracks 23 body zones. Each zone has specific depth, tissue type, and recommended protocol considerations.

Key contraindications include active cancer in the treatment area, pregnancy over the abdomen, epilepsy (with flashing lights), and concurrent photosensitizing medications.

PBM studies use sham devices (identical appearance but no therapeutic light output) as placebos. Grade A evidence requires multiple positive double-blind RCTs.

Meta-analyses of PBM research have been published for many conditions including acne, wound healing, pain, and depression.

Systematic reviews assess study quality and synthesize findings. They form the basis for evidence grades and clinical guidelines.

Grade A: multiple positive RCTs. Grade B: limited RCTs with positive results. Grade C: preliminary evidence, small studies. Grade D: insufficient data to draw conclusions.

Eligibility depends on the specific device, your plan, and whether you have a Letter of Medical Necessity. Check with your plan administrator.

Several laser hair growth caps have received 510(k) clearance. Most LED panels are registered but not 510(k) cleared.