How often should you use a red LED mask? A sham-controlled trial

What they did

Ninety-five women were assigned to three sessions a week, two sessions a week, or a sham mask, for four weeks. The mask emitted 660 nm red light at 6.4 mW/cm² for 21 minutes, about 8 J/cm² per session. Participants did not know which group they were in.

Blinded specialists scored standardised photos on a wrinkle scale. Software measured wrinkle lengths, and participants completed a satisfaction questionnaire.

What they found

On the specialists’ wrinkle scale, there was no meaningful difference between any of the groups, including sham.

Software measurements showed shorter frown lines and right-eye wrinkles in both real-light groups compared with sham. Satisfaction was 80% and 73% in the three- and two-session groups, both significantly above sham.

Three sessions did not do more than two.

What it cannot tell you

The visible-grade result was null. Changes showed up on software measurement and in satisfaction, not on the clinicians’ scale.

In short

A well-controlled mask trial with a modest result. Two sessions a week matched three, and the visible change was small.

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.