A controlled trial compared red-only light against a broader polychromatic spectrum extending into near-infrared. Both worked. The broader spectrum showed no advantage over red alone — which is worth knowing when a device charges a premium for more wavelengths.
The comparison
Wunsch and Matuschka's 2014 study in Photomedicine and Laser Surgery was designed to answer this. 136 volunteers, 113 randomised across treatment groups, 23 controls. One group received 611–650nm — essentially red only. Another received 570–850nm, a broad polychromatic band reaching into near-infrared.
Both groups were treated twice weekly for 30 sessions. Outcomes were measured by ultrasound collagen density, computerised digital profilometry, blinded photographic assessment and patient satisfaction.
Both light sources demonstrated efficacy and safety for skin rejuvenation and increased intradermal collagen against controls. The broadband polychromatic treatment showed no advantage over the red-only spectrum.
Why this matters commercially
Device marketing in this category tends to compete on wavelength count. Four wavelengths, six wavelengths, amber plus red plus deep red plus near-infrared. The implication is that more is better.
For facial skin rejuvenation specifically, this trial does not support that implication. Adding near-infrared to red did not improve the measured outcome.
That is not a claim that near-infrared is useless. It penetrates deeper and is studied for different applications — muscle, joints, deeper tissue. It is a narrower point: for the outcome most people buy a facial device for, the red band was already doing the work.
How to read a spec sheet
Two questions worth asking of any device.
Is the wavelength published at all? "Red light therapy" without a number in nanometres is not a specification.
Is the extra wavelength doing something for your concern? Near-infrared on a facial device is not wrong. It is just not established as better for facial rejuvenation than red alone.
What we chose
The GlowLift Pro uses 660nm rather than a broad spectrum — the wavelength with the most direct evidence behind it for dermal collagen, and the one Barolet's 2009 work used specifically.
Where we did add technologies, we added different mechanisms rather than more wavelengths: microcurrent for muscle tone, warmth for absorption, sonic vibration for puffiness. Those address things light does not.
References
- Wunsch A, Matuschka K. A controlled trial to determine the efficacy of red and near-infrared light treatment in patient satisfaction, reduction of fine lines, wrinkles, skin roughness, and intradermal collagen density increase. Photomed Laser Surg. 2014;32(2):93–100. Journal
- Barolet D, et al. Regulation of skin collagen metabolism in vitro using a pulsed 660 nm LED light source. J Invest Dermatol. 2009;129(12):2751–2759. PubMed
Roveo devices are cosmetic products, not medical devices.