Do LED masks work?

You’ve probably noticed this scene on social media: people (usually women) lounging on couches or in beds while wearing serial killer-style masks with colored lights emanating from underneath them.

Commonly called light therapy or LED masks, these devices use light-emitting diodes to shine light at specific wavelengths onto the skin for a variety of purposes, such as reducing wrinkles, tightening the skin, and controlling acne.

The devices, also available in wand form, are popular. They can also be expensive, with some costing several thousand dollars.

Do they work? We asked two dermatologists and two facial plastic surgeons for their opinions.

What is light therapy used for?

LED masks have holes for the eyes and mouth and are usually held in place with straps. The handheld wands are lightly pressed against the skin and moved slowly. Both bathe the skin in different wavelengths of light, depending on what they are trying to accomplish.

Many devices emit red light with a wavelength between 630 and 700 nanometers. Red light can penetrate deep into the skin to stimulate the production of collagen and elastin, proteins that help maintain skin strength and elasticity, said Dr. Akshay Sanan, a facial plastic surgeon in Boston. By stimulating these proteins, red light can minimize wrinkles and help skin look younger. It can also “reduce inflammation and speed healing,” Dr. Sanan said.

Other devices emit near-infrared light, about 700 nanometers or more, which can promote wound healing and reduce chronic inflammation, Dr. Sanan said.