Is it a gimmick or does it actually work? We investigated to see if light therapy devices increase hair growth. What we found out was exciting and disappointing all at once. Let’s start with the good news.
The good news
We looked at several clinical studies from the 1960s to the present. Each one used red or infrared light on either animal or human test subjects. And in each case, the light stimulated hair growth. Hair grew back regardless of what caused the hair loss.
Some delivery methods worked better than others. But neither animals nor people suffered side effects. Moreover, low-level light therapy was effective on both men and women. It reversed hereditary androgenetic alopecia, alopecia areata, and hair loss from chemotherapy. It even sped up hair growth when the hair had been purposefully shaved or removed.
Scientists say that red light therapy works because it shifts hair follicles into the anagen, or growth phase. It encourages activity at a cellular level. Furthermore, it accomplishes this with only a few minutes exposure a day.
But to be fair, there’s some bad news too.
The bad news
Even though they’ve studied light therapy for decades, scientists aren’t sure exactly what the exact ideal wavelength is for hair growth. They have a ballpark figure only. That’s why some hair growth devices incorporate more than one wavelength, like 630 to 655nm. Overall, 650nm seems to be the sweet spot.
Clinical studies also haven’t concluded whether continuous or pulsed light is better. And we also aren’t certain if including near-infrared light increases hair re-growth.
To conclude, yes, red light therapy grows back hair. It stimulates follicles to begin producing hair again. Moreover, it works on women and men who have lost their hair due to various reasons. Best of all, there are no negative side effects.