Different light, different outcomes. Light consists of photon packets that carry energy measured in nanometers.[1] Scientists classify these wavelengths into distinct energy bands, including ultraviolet, visible, and infrared light. Each band contains specific peak energies that cells absorb most effectively.

Within the red and near-infrared spectrum, different wavelengths produce distinct therapeutic effects. Red light therapy typically spans 620 to 850 nanometers; each specific wavelength targets different cellular processes and healing mechanisms. Though these wavelengths may appear similar, each creates unique biological responses that optimize cellular function and promote healing.

What is Photobiomodulation?

Photobiomodulation refers to the process in which specific wavelengths of light trigger beneficial biological responses at the cellular level.[2] This therapeutic approach uses red and near-infrared light to stimulate mitochondrial function, enhance cellular energy production, and activate natural healing processes throughout the body. The light penetrates tissues and gets absorbed by cellular components, particularly cytochrome c oxidase in the mitochondria, leading to increased ATP production and improved cellular metabolism.

Research supports the effectiveness of photobiomodulation in reducing inflammation, accelerating tissue repair, improving circulation, and providing analgesic effects on nerve pathways. Over 6,000 clinical trials demonstrate its systemic benefits when applied through full-body systems. ARRC LED devices incorporate advanced frequency augmentation, longer wavelengths, and optimized power delivery to create a new class of devices that deliver superior therapeutic outcomes for healing.

A Breakdown of The Different Wavelengths

Multiwave photobiomodulation systems utilize different wavelengths of energy to stimulate multiple healing responses at varying tissue depths, targeting different cell types. Each wavelength creates distinct therapeutic effects, from surface-level skin treatments to deep tissue penetration that reaches organs and connective tissues:[3]

UV light (10 to 310 nanometers): May cause skin tanning and damage. High-intensity LED photobiomodulation systems in the visible and near-infrared spectrum typically contain no UV light
Visible blue (415 and 470 nanometers): Demonstrates antiviral and antibacterial properties depending on the specific wavelength. The 417-nanometer range works effectively for acne, while 470 nanometers targets MRSA. The 450-nanometer blue addresses seasonal affective disorder, and recent studies suggest blue light accelerates wound healing and provides pain relief
Visible green (528 nanometers): Stimulates both blood flow quality and quantity. Green light accelerates wound healing through positive effects on hemoglobin. Research indicates that 528-nanometer green light is effective in addressing neuropathy, diabetes, shingles, and acne. Blood-based conditions may benefit significantly from green wavelengths
Visible red (630 to 660 nanometers): Activates cellular energy, detoxifies cells, and builds new arteries. Red 633 nanometers targets skin tone through collagen and elastin stimulation, while 660 nanometers influences ATP production more effectively. Recent studies use 640-nanometer red for performance enhancement
Near infrared (810, 830, 850, 880, and 940 nanometers): Penetrates deeper into connective tissues and organs. These wavelengths remain invisible to the naked eye. The 810-nanometer wavelength achieves the deepest penetration, reaching deeper muscles, connective tissues, and organs. Longer wavelengths, like 880 and 940 nanometers, create cellular heat
Far infrared (940 to 1000+ nanometers): Heats nanowater in cell membranes, similar to far infrared sauna effects. Most photobiomodulation systems avoid far infrared because they focus on mitochondrial stimulation rather than heat-based detoxification

What nm is Red Light?

Red light wavelength spans the visible spectrum from approximately 620 to 700 nanometers, with red light therapy wavelengths typically focusing on the 630 to 660-nanometer range for optimal therapeutic benefits. The best nm for red light therapy varies by treatment goal — 630 nanometers targets surface-level skin conditions and collagen production, while 660nm penetrates deeper to enhance ATP production and cellular energy.

When comparing 660nm vs 850nm, the 660-nanometer red light wavelength for skin remains visible and works primarily on surface tissues, whereas 850 nm enters the near-infrared range for deeper tissue penetration.

The Science Behind Photobiomodulation Wavelengths

Red light therapy encompasses more than just visible red light. This therapeutic approach uses wavelengths in both the visible red spectrum and the invisible near-infrared range to target different cellular processes and tissue depths.[4]

Laser versus LED delivery is often the primary difference in light therapy devices. Low-level laser therapy delivers the same therapeutic wavelengths as LED-based systems but uses “cold” lasers instead of light-emitting diode bulbs. Laser treatments typically occur in clinical settings, while LED-based red and near-infrared devices are widely available for home use.
Near-infrared positioning falls within the infrared spectrum, ranging from 780 to 1,200 nanometers, which places it on the shorter end of the infrared frequency spectrum. At this range, the body still perceives the energy as light rather than heat, which distinguishes therapeutic near-infrared from the heat-generating far-infrared wavelengths used in saunas.

Why is Red Light Treatment Effective?

Red light treatment achieves therapeutic results through specific biological mechanisms that occur when cells absorb optimal wavelengths of red light. The red light therapy spectrum targets cellular components, triggering a host of beneficial physiological responses:[5]

Mitochondrial stimulation: Red light with wavelengths between 630 and 660 nanometers is absorbed by cytochrome c oxidase, the final enzyme in the cellular respiratory chain, thereby increasing ATP production and cellular energy
Enhanced circulation: The red light spectrum wavelength promotes vasodilation and improved blood flow, delivering more oxygen and nutrients to tissues while removing metabolic waste products
Reduced inflammation: Targeted frequency red light exposure modulates inflammatory responses at the cellular level, decreasing pro-inflammatory cytokines and promoting anti-inflammatory pathways
Collagen production: The optimal red light wavelength and frequency stimulate fibroblasts to produce more collagen and elastin, improving skin texture, elasticity, and wound healing rates
Cellular detoxification: Red light therapy enhances cellular metabolism and waste removal processes, supporting the body’s natural detoxification mechanisms and improving overall cellular function

What Wavelength of Red Light Frequency is Best?

The optimal red light frequency depends on the specific therapeutic goals and target tissue depth. For surface-level skin conditions, such as fine lines, collagen production, and general skin health, wavelengths between 630 and 660 nanometers prove most effective because they penetrate the upper layers of the skin, where fibroblasts produce collagen and elastin. These shorter wavelengths within the red light therapy spectrum also enhance blood circulation and support wound healing at the cellular level, making them ideal for skincare applications and addressing superficial concerns.

For deeper tissue penetration and muscle recovery, near-infrared wavelengths between 810 and 850 nanometers deliver superior results. These longer wavelengths penetrate several centimeters into tissues, reaching mitochondria in deeper muscle layers to enhance ATP production and provide pain relief for conditions like joint pain.

Frequently Asked Questions About Red Light Wavelengths

Sources

[1] Blair, B. (n.d.). The Basics of Light. Blair.pha.jhu.edu. https://blair.pha.jhu.edu/spectroscopy/basics.html on June 11, 2025

[2] Anders, J. J. (2016, June 27). Photobiomodulation. Www.aslms.org. https://www.aslms.org/for-the-public/treatments-using-lasers-and-energy-based-devices/photobiomodulation on June 11, 2025

[3] Felician, M. C. P., Belotto, R., Tardivo, J. P., Baptista, M. S., & Martins, W. K. (2023). Photobiomodulation: Cellular, molecular, and clinical aspects. Journal of Photochemistry and Photobiology, 17, 100197. https://www.sciencedirect.com/science/article/pii/S2666469023000386 on June 11, 2025

[4] 5 health benefits of red light therapy. (2025, April 30). Uclahealth.org; UCLA Health. https://www.uclahealth.org/news/article/5-health-benefits-red-light-therapy on June 11, 2025

[5] Heiskanen, V., & Hamblin, M. R. (2018). Photobiomodulation: lasers vs. light emitting diodes? Photochemical & Photobiological Sciences, 17(8), 1003–1017. https://pmc.ncbi.nlm.nih.gov/articles/PMC6091542/ on June 12, 2025

What Wavelength is Best for Red Light Therapy?

The optimal wavelengths for red light therapy depend on an individual’s specific wellness goals and the target conditions being addressed. Shorter wavelengths, between 630-660 nanometers, excel at treating skin conditions such as fine lines, acne, and psoriasis, while stimulating collagen production through the activation of fibroblasts. These specific wavelengths within the visible light spectrum enhance blood flow and support wound healing at the cellular level.

For deeper therapeutic benefits, such as muscle recovery and joint pain relief, longer wavelengths in the near-infrared range (810-850 nanometers) penetrate tissues more effectively, reaching mitochondria and boosting ATP production. Many modern red light therapy devices designed for home use combine different wavelengths to maximize the benefits of red light therapy across multiple tissue depths and cellular processes.

What’s the Difference Between Red Light and Near-Infrared Light?

Red light therapy utilizes wavelengths of red light in the 630-700 nanometer range, which are visible to the human eye, primarily targeting surface tissues for skincare and skin health applications. Near infrared light operates at wavelengths between 700 and 1000 nanometers, making it invisible while providing superior tissue penetration for infrared light therapy. NIR light effectively reaches deeper structures to enhance blood circulation, reduce inflammation, and promote muscle recovery.

Both forms of photobiomodulation stimulate cellular light energy absorption; however, near-infrared light therapy can access tissues that standard red light therapy cannot effectively penetrate, making it ideal for addressing joint pain and promoting deeper healing processes.

How to Determine if the Red Light Device Is Using the Correct Wavelengths?

Quality red light therapy devices should clearly specify their exact wavelengths in nanometers rather than using vague terms. Look for light-emitting diode devices that utilize proven therapeutic wavelengths, such as 630, 660, 810, or 850 nanometers, backed by clinical research. Reputable phototherapy devices will provide detailed specifications about their light spectrum, irradiance levels, and light source quality. Avoid devices that only mention general terms without specific wavelength measurements, as these may not deliver the therapeutic health benefits associated with proper photobiomodulation.

Can Different Wavelengths Be Used at the Same Time?

Yes, combining different wavelengths simultaneously often produces superior results compared to single-wavelength treatments. This multi-wave photobiomodulation approach enables the user to target multiple cellular processes and tissue depths in a single session, thereby maximizing the effectiveness of red light therapy. Advanced red light therapy devices integrate both visible light and near-infrared wavelengths to address surface skin conditions while promoting deeper muscle recovery and pain relief. Modern LED light systems designed for at-home use make this multiwave approach accessible for daily wellness routines without the need for clinical low-level laser therapy sessions.