Why Use NIR Instead of Red Light? The Science-backed Answer

Light isn’t just light. Within the red and near-infrared spectrum, different wavelengths reach different depths, speak to different tissues, and activate different layers of human biology. It’s why in photobiomodulation research, precision matters. And it’s why our devices are engineered with both red (660 nm) and near-infrared (850 nm) wavelengths.

The short version: red light supports surface-level repair, while near-infrared reaches deeper structures like muscle and connective tissue. They don’t compete; they complement each other.

This is how science breaks it down.

The Depth Story: Where Each Wavelength Travels

Red light (660 nm) is visible to the eye and penetrates roughly 0.5-1 mm into the skin.[1] This places it within the epidermis and upper dermis, layers rich in fibroblasts and extracellular matrix - a mix of proteins, including collagen and elastin architecture. At this depth, red wavelengths are absorbed by cellular chromophores such as cytochrome c oxidase, boosting ATP production, cellular metabolism and healthier cellular responses.[2,3]

Near-infrared (850 nm) is invisible to the human eye, but it travels further into the skin. It experiences less scattering by melanin and haemoglobin, allowing it to reach a few more millimetres into deeper tissues – muscle fibres, connective tissue, and joints.[1] Once there, it supports mitochondrial respiration in deeper structures. Near-infrared (NIR) is widely studied for muscle and joint recovery.[4,5]

Two wavelengths. Two different biological conversations.

What they activate at the cellular level

Red light and NIR activate photobiomodulation through similar mechanisms, but in different locations:

Red light (660 nm) works at the skin’s surface:

• Absorbed by cytochrome c oxidase in skin cell mitochondria, supporting ATP production and healthy energy metabolism [2,6]
• Stimulates fibroblasts to produce collagen and elastin [7,8]
• Reduces pro-inflammatory signalling such as TNF-α and IL-6 in surface tissues [6]
• Supports the skin’s natural repair processes at a cellular level [8]

Near-infrared (850 nm) works deeper:

• Reaches mitochondria in muscle and connective tissue where it supports energy production and cellular repair [4,9]
• Associated with reduced post-exercise muscle soreness and faster recovery [9]
• Penetrates to areas where inflammation affects mobility and comfort [5]

Same mechanism. Different layers. Different benefits.

Why wavelength specificity matters

In photobiomodulation, “close enough” is not enough. The mitochondrial enzyme cytochrome c oxidase has distinct absorption peaks, particularly around 660 nm and 850 nm. That’s why research consistently shows these wavelengths to be the most effective for both surface and deep-tissue support.[3]

Mid-range wavelengths, such as 730 nm, fall into what researchers describe as a “therapeutic valley”, where biological absorption is dramatically lower.[1] Precision is the difference between a device that works and a device that merely glows.

Why Bon Charge Combine Both

Think of red and near-infrared as complementary. Red light energises and repairs at the surface, while NIR reaches beneath to support muscles, joints, and deeper cellular structures.

Used together, they create synergistic effects, addressing the energetic needs of both superficial and deeper tissues simultaneously.[7,8]

This is why most BON CHARGE devices include both: so every layer of tissue - from surface to deep tissue - receives the wavelength it needs.

Biological systems respond to light. And when you choose the right wavelength, you support biology at a very specific level.

BON CHARGE: This content is for general education and is not medical advice. Our products are not intended to diagnose, treat, cure, or prevent any disease. Always follow product instructions and consult a qualified healthcare professional for guidance tailored to you. Individual results may vary.

References

1. Zein, R., Selting, W. & Hamblin, M. R. Review of light parameters and photobiomodulation efficacy: dive into complexity. J. Biomed. Opt. 23, 120901 (2018). https://doi.org/10.1117/1.JBO.23.12.120901
2. de Almeida, P. et al. Red (660 nm) and infrared (830 nm) low-level laser therapy in skeletal muscle fatigue in humans: what is better? Lasers Med. Sci. 27, 453–458 (2012). https://doi.org/10.1007/s10103-011-0957-3
3. de Freitas, L. F. & Hamblin, M. R. Proposed mechanisms of photobiomodulation or low-level light therapy. IEEE J. Sel. Top. Quantum Electron. 22, 7000417 (2016). https://doi.org/10.1109/JSTQE.2016.2561201
4. Hamblin, M. R. & Demidova, T. N. Mechanisms of low level light therapy. Proc. SPIE 6140, 614001 (2006). https://doi.org/10.1117/12.646294
5. de Almeida, P. et al. Red (660 nm) and infrared (830 nm) low-level laser therapy in skeletal muscle fatigue in humans: what is better? Lasers Med. Sci. 27, 453–458 (2012). https://doi.org/10.1007/s10103-011-0957-3
6. Hamblin, M. R. Mechanisms and applications of the anti-inflammatory effects of photobiomodulation. AIMS Biophys. 4, 337–361 (2017). https://doi.org/10.3934/biophy.2017.3.337
7. Yamauchi, N. et al. High-intensity red light-emitting diode irradiation suppresses the inflammatory response of human periodontal ligament stem cells by promoting intracellular ATP synthesis. Life 12, 736 (2022). https://doi.org/10.3390/life12050736
8. Li, W.-H. et al. Low-level red plus near infrared lights combination induces expressions of collagen and elastin in human skin in vitro. Int. J. Cosmet. Sci. 43, 311–320 (2021). https://pubmed.ncbi.nlm.nih.gov/33594706/
9. Wunsch, A. & Matuschka, K. A controlled trial to determine the efficacy of red and near-infrared light treatment in patient satisfaction, reduction of fine lines, wrinkles, skin roughness, and intradermal collagen density increase. Photomed. Laser Surg. 32, 93–100 (2014). https://doi.org/10.1089/pho.2013.3616
10. Leal-Junior, E. C. P. et al. Effect of phototherapy (low-level laser therapy and light-emitting diode therapy) on exercise performance and markers of exercise recovery: a systematic review with meta-analysis. Lasers Med. Sci. 30, 925–939 (2015). https://doi.org/10.1007/s10103-013-1465-4