Wellness influencers tout the therapy's power for everything from rejuvenating skin and hair to boosting longevity. Devices sold for at-home use abound. We look at the evidence behind the hype.

In 2021, dermatologist David Ozog was on holiday with his family in the Bahamas, when his 18-year-old son had a massive stroke. The teenager was airlifted to Florida, and then to Chicago for surgery.

On a crisp night last fall in the Arizona desert, I stood amid sand and scrub at the intersection of Valencia and Kolb on the outskirts of Tucson and beheld a gleaming gas station. To say that this ...

Red light therapy has gone from dermatology clinics to the wellness world, promising everything from younger-looking skin and thicker hair to weight loss, pain relief, better sleep, and even improved ...