Pulsed 660 nm light, collagen production and wrinkle depth

What they did

First, the team grew human skin in the lab and gave it 11 sham or LED treatments with pulsed 660 nm light. They measured type-1 procollagen, the building block of collagen, and MMP-1.

Then they treated one side of the face in people with aged or sun-damaged skin for 12 sessions and compared it with the untreated side, with a blinded assessor scoring wrinkles.

What they found

In lab skin, LED treatment raised procollagen by 31% and lowered MMP-1 by 18% compared with untreated skin.

In people, more than 90% showed shallower wrinkles and smoother texture on surface scans, and 87% had a lower wrinkle severity score from the blinded assessor. No side effects or downtime were reported.

What it cannot tell you

The abstract does not give the number of people in the face study. The light was pulsed in a specific pattern, which home masks may not replicate.

In short

This study helps explain how red light may work: more collagen made and less broken down, followed by visible change on the face.

Masks with these wavelengths

One of the 10 masks in the comparison list a wavelength in the band used here (red near 660 nm). They are examples, listed alphabetically, each with our specification page and the manufacturer’s own product page. They are not recommendations, and the links carry no affiliate parameters.

• Dr. Renú SpectraLift Advanced465 · 530 · 630–660 · 850 nm · Dr. Renú product page

Matching a wavelength is not the same as matching the study. Dose, irradiance, session length and schedule also differ, and a mask’s reported output is not independently measured. See how dose works and home vs clinic doses.