Forest Light is the Future of Skin Health

Thomas P Seager, PhD
May 21
7 min read

Updated: May 24

Red light devices bypass the most critical chromophore.

Popular red light therapy devices use wavelengths that target cytochorme c oxidase (CcO) in mitochondria, bypassing the skin in favor of reaching tissues underneath. For skin health, use forest light (532 nm green + 730 nm red) to target melanin.

Why Most Red Light Misses the Skin

Red light photobiomodulation has exploded in popularity in the last ten years, and for good reason. When the wavelengths are chosen carefully, red and near-infrared (NIR) phototherapy will stimulate cytochrome c oxidase (CcO) inside mitochondria to accelerate production of ATP.

Graph showing absorption by CcO of different wavelengths of light — 670 nm light penetrates several millimeters below the skin where it will maximize ATP production in underlying tissues by targeting cytochrome c oxidase (CcO). 830 nm travels even farther, although it is less effective.

The problem with red light therapy for skin treatment is that most red light travels right past the skin before it can be absorbed by the CcO in the dermal mitochondria. That means red light therapy can be effective for muscles, tendons, and recovery of tissues below the skin, but slow to benefit the skin itself.

Generally speaking, the longer the wavelength of NIR light, the further that light travels into the body (Ko et al. 2023). Blue and violet light fail to penetrate further than the outer most skin cells, whereas green light (about 520 nm - 570 nm) reaches the dermal layers that are most responsible for structural support, strength, elasticity, nourishment, and immune defense, making green more efficient for promoting skin health. By contrast, red penetrates deeper and NIR bypasses the skin altogether.

The reason comes down to one molecule: melanin.

Illustration of the penetration of different wavelengths of light thru the skin. — Green light targets cells in the dermis layer. Red target the hypodermis. Near-infrared (NIR) bypasses the skin altogether (Ko et al. 2023).

Melanin, the Forgotten Chromophore

Every photobiomodulation device relies chromophores — a light-absorbing molecule in tissue that, when excited by specific wavelengths, initiates a downstream biological response. Right now, CcO dominates the photobiomodulation industry because red and near-infrared (NIR) wavelengths absorbed by CcO are promote electron transport inside mitochondria and boost ATP production (Wong-Riley et al., 2005).

Because ATP provides energy for growth, wound repair, muscle ,movement -- even thoughts and feelings -- promoting ATP production can enhance metabolism and improve almost every biological function in the body. This mechanism is well-documented in the scientific literature. But CcO is not the only photosensitive molecule in your skin. It's not even the most important one for skin-specific applications.

When it comes to skin health, there are three primary chromophores (Pinto et al., 2024):

melanin in the epidermis,
hemoglobin in the dermis,
and water throughout all layers, with longer wavelengths penetrating progressively deeper.

Melanin sits at the outermost layer of the skin — precisely where most dermatological applications need to act. It is melanin that pigments the skin, and most people understand the critical role of melanin in the out layers of the skin for protecting against the damaging effects of ultraviolet light. That's how a tan protects against sunburn.

What almost no one understand is that melanin also has absorption peaks at approximately 532 nm (green) and 730 nm (red/NIR) -- exactly the same wavelengths that dominate the light environment of the shady forest.

The only consumer photherapy/photobiomodulation device on the market today that is tuned to 532 & 730 nm to target melanin is the Forest Skinlight from MyGreen.

All the others target CcO.

Forest Skinlight

$249.00

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Melanin Absorbs Green Light

Melanin is best known as the pigment responsible for skin color and UV protection. When the skin is exposed to UVB, melanocytes synthesize new melanin, which redistributes through the upper layers to shield underlying DNA from damage. This is the familiar mechanism of tanning.

And melanin is far more than a passive shield. It is a highly photosensitive chromophore that converts absorbed light into electrochemical energy that skin cells use to perform work. That is, melanin in the skin's epidermal layer functions as a biological solar panel when illuminated with the wavelengths to which it is most sensitive.

A 2023 study from Northwestern University demonstrated that synthetic melanin particles applied topically to wounded mouse skin not only reduced inflammatory signaling but accelerated healing by boosting antioxidant enzyme activity — including superoxide dismutase, a key defender of mitochondrial integrity (Biyashev et al., 2023). The implication is that melanin doesn't just protect the skin -- it supports repair.

Forest Light is Nature's Remedy

Spectrographic studies of shady forest environments worldwide consistently show that the dominant wavelengths are green (~530-550 nm) and red/NIR (~730 nm) (Endler, 1993). Broadleaf canopies absorb red and blue wavelengths for photosynthesis, while reflecting and transmitting green and red/NIR.

Graph showing green light is most effective for promoting skin health — Green light accelerated wound healing faster than red (Fushimi et al. 2012 [mice]).

Japanese researchers compared the wound-closing efficacy of multiple LED wavelengths on murine skin lesions and found that 518 nm green light outperformed 638 nm red in the rate of wound closure. Green light upregulated fibroblast migration and collagen synthesis pathways better than red (Fushimi et al. 2012).

These findings were independently supported by another on diabetic wound healing, which found that both red (629 nm) and green (540 nm) LED treatments accelerated wound closure compared to controls (Dungel et al., 2023).

The mechanism may relate to the dose-dependence of melanin excitation. At low photon doses, absorbed green light generates charge gradients in melanin-rich skin cells that power fibroblast signaling and keratinocyte migration — the cellular machinery of wound repair. At high doses, delivered via pulsed picosecond lasers, the same wavelength (532 nm) destroys melanin clusters, making it an established tool in dermatology for treating age spots, freckles, and hyperpigmentation (Friedmann et al., 2022). The same chromophore, the same wavelength — but opposite biological outcomes depending on dose.

This is a classic example of hormesis: low-level stimulation activates a healing response; high-level stimulation destroys the target.

Green Light and Pigmentation Disorders

Because green light can energize melanin at low doses and destroy it at high doses, it is relevant to an wide range of skin conditions that may include treatment of hyperpigmentation (age spots, freckles, etc) and melanoma cancer. For example, 505 nm green LED irradiation inhibited melanin synthesis in human subjects, reducing hyperpigmentation without the risks associated with UV-based treatments (Yoshihito et al., 2025). Brazilian researchers published a complementary finding that 532 nm green light suppressed melanoma progression in skin cells, suggesting that energizing melanin at its peak absorption wavelength may inhibit the dysregulated proliferative signaling that drives malignancy (Haussman et al., 2022). In vitro models, animal studies, and clinical trials all demonstrate consistent reductions in pigmentation resulting from various green light therapies (Galache et al., 2024).

Red Light at 730 nm: The Overlooked Melanin Target

The role of red light in this framework deserves clarification. For the outer skin the relevant red wavelength is 730 nm, corresponding to the red absorption peak in melanin's spectral profile. This wavelength is almost never used in consumer devices, most of which cluster around 630–660 nm or 810–850 nm for CcO targeting.

Combining 532 nm green and 730 nm red creates a dual-band device tuned specifically to melanin — one that mirrors the natural spectral composition of shady forest light. Such a combination would be expected to energize the epidermal layer more effectively than any conventional red light panel, and wound healing data supports this expectation, with low fluences stimulating repair and higher fluences causing inhibition (Schalka et al., 2024).

What This Means for Phototherapy Practice

The implications of this research are profound.

First, red light panels tuned to CcO targets (630–850 nm) are not designed for skin surface applications, where melanin is the dominant chromophore (not CcO). They still provide benefit through CcO activation in deeper tissues, but for epidermal wound healing, pigmentation management, and skin rejuvenation, they are targeting the wrong chromophore.
Second, green light at 532 nm — long dismissed as less penetrating than red, and therefore less useful — is likely the most effective wavelength for surface-level skin applications precisely because of its shallow penetration and melanin specificity. This is an advantage, not a limitation, for skin treatments.

Human skin has been bathed in green and red/NIR forest light since Adam and Eve first populated the Garden of Eden. The problem is that we've replaced a forest green paradise with concrete, asphalt, steel & glass climated-controlled, fluorescent lighting, and LED screens.

The next wave of phototherapy isn't going to be bigger red light panels with more LEDs. It's wavelength-specific devices built around an understanding of what chromophores actually live where in the skin — and what happens when you give them exactly the photons they're designed to absorb.

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