LED light therapy has become one of the most popular non-invasive skincare treatments, but the reason it works is rooted in real cellular biology — not trends. The mechanism is called photobiomodulation, where specific wavelengths of light trigger beneficial changes inside skin cells.
What These Cellular Responses Can Do
When LED light reaches the skin, its photons are absorbed by light-sensitive molecules called chromophores, especially cytochrome c oxidase in the mitochondria. This absorption triggers a cascade of regenerative processes.
- Increase ATP production (the cell’s main energy source)
- Boost fibroblast activity (cells that create collagen + elastin)
- Stimulate collagen synthesis
- Reduce inflammation
- Improve circulation and tissue repair
A 2022 systematic review of 31 clinical trials confirmed consistent improvements: better collagen production, reduced wrinkles, faster healing, and reduced inflammation.
Why Different LED Colours Matter
Each LED colour reaches a different depth and interacts with different chromophores. This is why various wavelengths target different skin concerns.
Red Light (630–680 nm)
The most studied wavelength for anti-ageing.
Red light penetrates more deeply than other visible wavelengths and has strong evidence for skin rejuvenation.
What red light can do:
- Increase fibroblast activity
- Boost collagen + elastin
- Reduce fine lines and wrinkles
- Improve texture and firmness
Red light has the most robust clinical support for anti-ageing effects.
Near-Infrared Light (800–900 nm)
The deepest-penetrating and excellent for recovery.
Near-infrared (NIR) travels beyond the dermis, into deeper tissues. It doesn’t target pigmentation but plays a big role in repair.
Benefits of NIR:
- Enhances circulation
- Reduces inflammation
- Supports wound healing
- Improves deep tissue repair
NIR is ideal for recovery, sensitive skin, or those who undergo other skin treatments.
Blue Light (405–420 nm)
Targets acne — not ageing.
Blue light interacts with the porphyrins inside C. acnes bacteria.
What blue light does:
- Reduces acne-causing bacteria
- Helps calm active breakouts
- Reduces superficial inflammation
Blue is often combined with red light to offset irritation and support healing.
Yellow / Amber Light (570–590 nm)
Gentle, surface-level effects for calming and brightening.
Research on yellow LED is more limited than red or NIR, but existing data suggests benefits for superficial skin concerns.
Yellow light can help with:
- Reducing redness
- Improving overall radiance
- Supporting skin healing
- Calming sensitive or reactive skin
Some studies associate yellow light with improved lymphatic flow and reduced redness after procedures — making it a popular “post-treatment” wavelength.
Green Light (520–560 nm)
Supportive but not a primary anti-ageing wavelength.
Evidence for green LED is modest, but it may help with:
- Brightening
- Reducing pigmentation appearance
- Calming irritation
Green light is not a collagen-stimulating wavelength, but many devices include it for surface-level tone improvement.
The Bottom Line
LED therapy isn’t a skincare gimmick — it’s a scientifically supported treatment with decades of research behind it. Different wavelengths do different things, but together they can:
- Boost collagen
- Reduce inflammation
- Improve skin tone
- Support healing
- Enhance treatment recovery
Consistency and correct wavelength selection are key to seeing visible results.
Source (Editorial Citation)
Ngoc LL, Abbas MA, Hadi SM, et al. Utilization of Light-Emitting Diodes for Skin Therapy: Systematic Review and Meta-analysis. Photodermatology, Photoimmunology & Photomedicine. 2022.
