Photobiomodulation using LED light therapy

LED light therapy (also known as photobiomodulation or low-level light therapy) uses targeted light waves of specific colours to influence biological processes in cells. It promotes healing, reduces inflammation and can stimulate cell growth or regeneration, depending on the wavelength used.

Mechanisms of action

Stimulation of cellular processes: LED light, particularly in the red and near-infrared spectrum, stimulates the mitochondria, which increases energy production (ATP) in cells and thus supports healing and regeneration processes (Dungel et al., 2017; Van Griensven et al., 2015; Ryu et al., 2024; Siqueira, 2024).

Anti-inflammatory effects: LED therapy can dampen inflammatory responses by reducing the activation of immune cells and the release of pro-inflammatory mediators (e.g. IL-1β, IL-18). This has been demonstrated, for example, in cases of brain damage following a stroke (Kim et al., 2017).

Promotion of cell growth and wound healing: Red and green LED light enhance cell proliferation and migration, which accelerates wound healing. Blue light, on the other hand, can inhibit cell growth and promote apoptosis (programmed cell death) (Dungel et al., 2017; Van Griensven et al., 2015).

Areas of application Scope of application Effect/outcome Wavelength Sources

Wound healing Faster healing, increased cell growth Red, green (Dungel et al., 2017; Van Griensven et al., 2015; Ablon, 2018)

Anti-inflammatory Reduced inflammation, less cell damage Red (Kim et al., 2017; Rucco et al., 2018)

Dermatology Treatment of acne, psoriasis, skin ageing, hair loss Blue, red, infrared (Ablon, 2018; Rucco et al., 2018)

Neurological disorders Protection and regeneration of nerve cells, e.g. following a stroke or nerve damage Red, infrared (Kim et al., 2017; Ryu et al., 2024; Siqueira, 2024)

Wavelengths and effects

Blue light (approx. 415–475 nm): Effective against acne; may inhibit cell growth (Van Griensven et al., 2015; Ablon, 2018).

Green light (approx. 516 nm): Promotes cell proliferation and migration, particularly in vascular cells (Dungel et al., 2017).

Red light (approx. 630–660 nm): Promotes healing, cell growth, anti-inflammatory effects and regeneration (Dungel et al., 2017; Van Griensven et al., 2015; Ablon, 2018; Khoo et al., 2020; Ryu et al., 2024).

Infrared (approx. 830 nm): Supports deeper tissues, e.g. nerve regeneration (Ryu et al., 2024; Siqueira, 2024).

Conclusion

LED light therapy works by specifically influencing cellular processes: it can accelerate healing, inhibit inflammation and promote tissue regeneration. The effects depend heavily on the chosen wavelength and are already being successfully utilised in many medical fields.

References

Kim, N., Lee, S., Park, K., Shin, Y., Choi, B., Shin, H., & Lee, H. (2017). Low-level light-emitting diode (LED) therapy suppresses inflammasome-mediated brain damage in experimental ischaemic stroke. Journal of Biophotonics, 10https://doi.org/10.1002/jbio.201600244

Dungel, P., Mühleder, S., Slezak, P., Rohringer, S., Pill, K., Chaudary, S., Priglinger, E., Holnthoner, W., Strassl, M., & Redl, H. (2017). The impact of wavelengths of LED light therapy on endothelial cells. Scientific Reports, 7. https://doi.org/10.1038/s41598-017-11061-y

Van Griensven, M., Dungel, P., Balmayor, E., Teuschl, A., & Redl, H. (2015). Phototherapy with LED light modulates healing processes in an in vitro scratch-wound model using three different cell types. Dermatologic Surgery, 41, 261–268. https://doi.org/10.1097/DSS.0000000000000266

Ablon, G. (2018). Phototherapy with Light-Emitting Diodes: Treating a Broad Range of Medical and Aesthetic Conditions in Dermatology. The Journal of Clinical and Aesthetic Dermatology, 11(2), 21–27.

Khoo, B., Yang, K., Ong, M., Sreeramanan, S., & Yoong, I. (2020). In vitro anti-breast cancer studies of LED red light therapy via autophagy. Breast Cancer, 28, 60–66. https://doi.org/10.1007/s12282-020-01128-6

Ryu, J., Limanjaya, A., & Suh, J. (2024). (276) Light-emitting diodes (LEDs) as a potential therapy for erectile function: a preclinical study in a cavernous nerve injury model. The Journal of Sexual Medicine. https://doi.org/10.1093/jsxmed/qdae002.239

Siqueira, R. (2024). Photobiomodulation Using Light-Emitting Diodes (LEDs) for the Treatment of Retinal Diseases. Clinical Ophthalmology (Auckland, N.Z.), 18, 215–225. https://doi.org/10.2147/OPTH.S441962

Rucco, M., Sorbellini, E., & Rinaldi, F. (2018). Photodynamic and photobiological effects of light-emitting diode (LED) therapy in dermatological diseases: an update. Lasers in Medical Science, 33, 1431–1439. https://doi.org/10.1007/s10103-018-2584-8