How Green Light Heals Skin
- Thomas P Seager, PhD
- 9 hours ago
- 5 min read
Combine green and red light for fast skin healing
Summary
Red light therapy devices mostly bypass the skin, making them inefficient for treating skin defects.
Several studies, in animals and humans, comparing different wavelengths of light exposure demonstrate that green light best promotes skin healing.
The MyGreen Forest Skinlight combines green and red, making it the world's most effective photobiomodulation therapy device for restoring damaged or ageing skin.
Green Light Photobiomodulation for Wound Care
Red light photobiomodulation (PBM) promote healing in muscles, tendons, ligaments -- even brain cells -- far below the surface of the skin. That's because most of the energy in the longer wavelengths of near-infrared (NIR) travel straight past the epidermis and dermis so they can reach cytochrome c oxidase (CcO) in mitochondria deeper within the body (Cios et al. 2021). Only the red wavelengths (630 - 700 nm) energize CcO in the skin.
For skin health, targeting melanin with shorter wavelengths is a better choice than targeting CcO. Melanin already dominates photosensitivity in skin cells. It is the pigment that darkens skin in response to ultraviolet (UV) light exposure, and consequently it is the target chromophore for tanning beds and lamps. The problem is that UV wavelengths can damage skin, so it's not the right choice for PBM that is supposed to promote healing.
Fortunately, melanin also absorbs green light. When researchers in Osaka Japan tested blue, green, and red LED light on skin wounds in lab mice, they discovered that green (518 nm) promoted healing best -- even faster than red (Fushimi et al. 2012).
After seven days, green-treated wounds had shrunk to roughly a quarter of their original size, while untreated wounds still covered more than half the starting area. Full skin regrowth arrived two days earlier with both red and green light than with blue or no treatment.
To understand why, the Japanese researchers exposed human skin fibroblasts to the same LED wavelengths and measured the biological response. Green light triggered a surge in three key signaling molecules — leptin, IL-8, and VEGF — none of which were increased by red or blue light alone. These are the signaling molecules that promote cell growth, build new blood vessels, and restore skin elasticity.
Green Light Builds New Blood Vessels
One of the most important things a healing wound needs is a new blood supply. Without fresh vasculature, tissue cannot receive oxygen and nutrients, and repair stalls. A 2013 study from Brazil addressed this directly, comparing the angiogenic effects of red and infrared lasers alongside red, green, and blue LEDs on rat wounds. By counting newly formed blood vessels under the microscope eight days after injury, the researchers found that green and red LEDs produced the highest vessel counts — significantly greater than blue LEDs or untreated controls. Of course, the green LED produced the most pronounced angiogenesis of any group tested (de Sousa et al. 2013).
Four years after the Brazilian study, a research team in Austria was able to translate results from animal models to human tissue. The exposed endothelial cells fro human umbilical tissue to blue (475 nm), green (516 nm), and red (635 nm) wavelengths of light to study which best promoted growth. Once again, it was green (Rohringer et al. 2017). They found that green light specifically elevated hepatocyte growth factor (HGF), a potent pro-angiogenic molecule also flagged by the original Japanese work. They also noted that green and red work along different molecular pathways, such that the two lights together could complement each other therapeutically.
The Mechanism: Powering Up Skin Cells
Most recently, a South Korea (Lee et al. 2025) used whole-transcriptome RNA sequencing to study healing in wounded olive flounder — a fish species increasingly used as a model for skin healing. The researchers exposed fish with standardized wounds to ambient, white, blue, and green LEDs for four weeks. At 28 days, green-LED fish had achieved 82% wound closure, compared to 63% for white light, 59% for blue, and just 49% for the untreated controls.
The transcriptomic data revealed why. Green light specifically activated genes associated with oxidative phosphorylation in mitochondria — the cellular machinery responsible for converting nutrients into ATP, the energy currency of the cell. Key mitochondrial complexes (I, IV, and V) were upregulated, including CcO, even though it was not the primary target of the light therapy. In other words, green light energy was converted into a surge of ATP production in the mitochondria, even though the reaction originated in melanin. Notably, oxidative stress markers were unchanged, indicating that green light promotes healing through energetic stimulation rather than by ramping up potentially damaging reactive oxygen species (Lee et al. 2025).
MyGreen Forest Skinlight
By replicating the green and red wavelengths of light that dominate the light environment of the shady forest, the MyGreen Skinlight leverages both melanin and CcO chromophores in the layers of skin most critical to promote healing: the epidermis and dermis. Although the LED light is small, it is so much more efficient for promoting skin health that it can do the same work as larger, more powerful, and more expensive devices that are using wavelengths that bypass the skin.
Testing of the Forest Skinlight on skin lesions caused by abrasions, burns, and surgery confirms the clinical expectations. One customer posted this definitive review:
"I began using this green light torch four weeks after undergoing Mohs surgery on my cheek and jawline.
"At the start, my 4-inch incision was raised, red, and still quite inflamed. I’ve stayed consistent for three weeks now, using it at least once a day during my nightly routine and occasionally adding a second session in the morning.
"The results have been incredible. The redness and swelling decreased significantly, and the light even seemed to help my skin purge the remaining dissolvable stitches. The incision is now almost entirely flat and barely noticeable. If you are dealing with post-surgical inflammation or raised scarring, I highly recommend this." - MyGreen Forest Skinlight customer review
References
de Sousa AP, Paraguassú GM, Silveira NT, de Souza J, Cangussú MC, dos Santos JN, Pinheiro AL. Laser and LED phototherapies on angiogenesis. Lasers in medical science. 2013 May;28(3):981-7.
Cios A, Ciepielak M, Szymański Ł, Lewicka A, Cierniak S, Stankiewicz W, Mendrycka M, Lewicki S. Effect of different wavelengths of laser irradiation on the skin cells. International journal of molecular sciences. 2021 Feb 28;22(5):2437.
Fushimi T, Inui S, Nakajima T, Ogasawara M, Hosokawa K, Itami S. Green light emitting diodes accelerate wound healing: characterization of the effect and its molecular basis in vitro and in vivo. Wound Repair and Regeneration. 2012 Mar;20(2):226-35.
Lee JY, Lee Y, Park J, Kang HY, Heo YU, Kim A, Kim N, Roh H, Kim DH. Molecular mechanisms of green LED-accelerated wound healing in olive flounder (Paralichthys olivaceus). Aquaculture. 2025 May 15;601:742267.
Rohringer S, Holnthoner W, Chaudary S, Slezak P, Priglinger E, Strassl M, Pill K, Mühleder S, Redl H, Dungel P. The impact of wavelengths of LED light-therapy on endothelial cells. Scientific reports. 2017 Sep 6;7(1):10700.
About the Author
Thomas P Seager, PhD is an Associate Professor in the School of Sustainable Engineering at Arizona State University. He is the founder of MyGreen Lamp, LLC and principal inventor of MyGreen products, and CEO of the Morozko Forge ice bath company.