The 9 Best Hair Growth Devices, According to Dermatologists

LED light may sound like a newfangled technology but it’s been well-studied for hair loss for over 20 years, says Dr. Finney. “A hair contains cells at its base that help to regenerate it called the hair bulge cells,” he says. “Red light between 620-678nm has been shown to target these bulge cells to help activate them, recruit a better blood supply, reduce inflammation and increase local nitrous oxide production which has been postulated to help reduce DHT.”

Keep in mind, however, that LED therapy has only been studied in genetic hair loss and in order for it to work, the light must be able to reach directly to the scalp.

One caveat: while red light therapy has been shown in studies to improve hair growth, it’s only been studied in Fitzpatrick skin types I-IV, says Dr. Kash. That’s not to say it won’t work for darker skin types V and VI, but it’s something to keep in mind when choosing and using an LED device.