Red light and infrared get mentioned in the same breath so often that people assume they're interchangeable. They're not — and the difference is simple once you see it on a spectrum.
It comes down to wavelength
Light is measured in nanometres (nm), and that number determines both its colour and how it behaves in skin:
- Red light (~630–660nm) is at the far end of what your eyes can see — the visible red glow an LED mask gives off. It's absorbed mostly in the upper layers of skin.
- Near-infrared (~800–850nm) sits just beyond visible red. Your eyes can't see it, so a near-infrared LED can look "off" while it's actually working. It penetrates deeper into tissue than visible red.
"Near-infrared" (NIR) just means the part of the infrared band closest to visible light. It's different from the "far-infrared" heat you feel from a sauna — near-infrared at these levels isn't about warmth.
Why the good masks use both
Because they reach different depths, red and near-infrared are complementary rather than competing. Pairing ~633nm red with ~830nm near-infrared covers more of the skin's layers than either alone — which is exactly why that combination became the standard in clinic-grade equipment, and why the serious at-home masks (Omnilux, CurrentBody, and Rosalume) all centre on it.
What this means when you're comparing masks
- Check both bands are present. A mask that's only visible red is missing the deeper-reaching half of the proven pairing.
- Don't be dazzled by brightness. Because near-infrared is invisible, a mask can look less "powerful" while delivering more total light. Brightness to your eye is not a measure of output — irradiance is.
- Ignore the extra colours, mostly. Blue, amber and green make longer spec sheets, but the red + near-infrared pairing is where the appearance evidence concentrates.
The note at the end of every Rosalume article: changes in skin appearance from light therapy build over 8–12 weeks of consistent use, 3–5 sessions a week. Gradual, not dramatic. Any brand — ours included — promising more than that is selling, not informing.
Rosalume is a Perth-founded red + near-infrared mask launching soon at $349, with published, independently verified output specs. Join the launch list or read our straight-answer FAQ.