LED Phototherapy: Targets of Red, Blue and Yellow Light and Their Evidence
The Principle
Unlike lasers’ destructive heat, LED therapy is photobiomodulation: low irradiance (typically 10-100 mW/cm², non-thermal) is absorbed by photoacceptors such as cytochrome c oxidase, influencing mitochondrial function and upregulating ATP and repair-related genes. It does not heat tissue — it recharges cells.
Band Division
| Band | Depth | Main target | Typical use |
|---|---|---|---|
| Blue 415 nm | Shallow | C. acnes porphyrins | Inflammatory acne adjunct |
| Yellow/amber 590 nm | Mid | Lymphatic, soothing | Redness, sensitive skin |
| Red 633 nm | Deeper (1-3 mm) | Fibroblasts, mitochondria | Repair, anti-inflammation, photoaging adjunct |
| NIR 830-850 nm | Deepest | Deep repair | Post-procedure recovery |
Dosing and Course
Photobiomodulation has a dose window: too little does nothing, too much inhibits (biphasic dose response). Typical: 10-20 minutes, 2-3 times weekly, 4-8 weeks per course. Painless, non-invasive, zero downtime — LED is the stacking modality: post-laser repair, post-op swelling, and standard skin-management bundles.
Honest Evidence Boundaries
- Good evidence: mild inflammatory acne adjunct, accelerated repair after procedures, photoaging adjunct.
- Modest: hair growth (red light is FDA-cleared for androgenetic alopecia adjunct), melasma (adjunct only).
- Weak: standalone anti-aging workhorse; fat loss claims.
LEIJEX’s LED panel system configures arrays for face, scalp and body scenarios.
FAQ
Big panels vs cheap handhelds?
Irradiance and distance are everything: qualified panels far outperform budget handhelds in energy density and uniformity. Judge by measured mW/cm², not LED count.
Do I need to avoid light after LED?
No. LED carries no UV and low energy — resume normal activity. Only photodynamic therapy (topical photosensitizer) requires strict photoprotection.