The main differences between red light and near infrared light (NIR) are their wavelength, penetration depth, and bio-effects. Below is a detailed comparison and guide on how to choose the right wavelength for your needs:
- Wavelength and penetration depth
Parameters Red light Near infrared light (NIR)
Wavelength range 600–700 nm (e.g. 660 nm) 700–1100 nm (e.g. 850 nm)
Penetration depth 1–5 mm (skin layer) 5–10 cm (muscles, bones, joints)
Primary targets Skin, superficial tissues Deep tissues, organs, brain
Importance:
Red light is very beneficial for skin health (collagen production, wound healing).
NIR light reaches muscles, tendons, and joints, providing better pain relief and improved recovery.
- Bio-effects
Red light (e.g. 660nm)
Boosts collagen and elastin production → anti-aging, reduces acne/scars.
Reduce surface inflammation (e.g. sunburn, eczema).
Stimulate hair follicles (for hair growth devices).
Near infrared light (e.g. 850nm)
Accelerate muscle repair → post-exercise recovery, relieve delayed onset muscle soreness (DOMS).
Reduce deep inflammation (e.g. arthritis, tendinitis).
Enhance brain function (emerging research in neuroprotection).
- How to choose the right wavelength?
For skin and beauty
Best: 660nm red light (e.g. for wrinkles, acne, rosacea).
Device:
Merican Red Light Therapy Panel M1
Pain and muscle recovery
Best: 850nm near infrared (or 660nm + 850nm dual wavelength).
Device:
Merican Red Light Therapy Panel M2
Joints and deep tissue
Best: 810nm or 850nm near infrared (can penetrate bones/tendons).
Example: Merican Red Light Therapy Bed M4N
Overall Health
Best: Red + NIR combination (e.g. 660nm + 850nm).
Example: Merican Red Light Therapy Bed M-MB
- Key Considerations
Dual wavelength devices (e.g. 660nm + 850nm) provide the broadest benefits.
Power density (≥50–100 mW/cm²) is more important than wavelength alone.
Avoid cheap devices with unproven wavelengths (ineffective or unsafe).
- Safety Tips
Eyes: NIR light penetrates eyelids → wear goggles for prolonged exposure.
Contraindications: Avoid if pregnant or with active cancer (consult your doctor).
Final Tip: If unsure, choose a red/NIR combination device (e.g. Merican). Start with 10–15 minutes, 3–5 times per week and adjust based on results.
