Two sessions or three? A red-mask trial

How the study worked

The 95 participants used a red mask twice weekly, three times weekly, or a sham mask for four weeks. The light was 660 nm at 6.4 mW/cm² for 21 minutes: about 8 J/cm² per session. Participants did not know their group.

Blinded specialists scored photos. Software measured wrinkle lengths, and participants rated their satisfaction.

The results

Specialists’ wrinkle scores did not differ meaningfully between the groups. Software found shorter frown lines and right-eye wrinkles in both real-light groups than in the sham group.

Satisfaction was 80% with three weekly sessions and 73% with two, both above sham. Three sessions did not produce more improvement than two.

What is still unclear

The specialist scores showed no benefit over sham. The positive findings came from software measurements and satisfaction ratings.

What to take from this

Two weekly sessions did as well as three in this trial. Specialist photo scores did not show a difference from sham.

Devices that list similar light

One of the 5 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. Related devices are examples, not evidence that a study tested that retail model.

• 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.