From reviewing archival footage—scrolling back 63,979 or so photos on my iPhone camera roll—it appears I shaved my head for the first time sometime in the spring of 2011. I was 30 years old, and it seemed like a logical choice given the slow thinning of my always-thin hair and the pleasantly round shape of my head.

When you don't have hair on your head, everyone assumes you're bald. I've always been quick to correct them that I, in fact, have hair—and it's not even receding. It was very thin and getting thinner. Since I was the kid whom nature denied a Vanilla Ice haircut a few short years after my mother denied me Hammer pants, my hair has always been fine and wispy.

Well, now I have hair again, thanks to eight weeks of using an LED cap made by GroWell. I don't have a lot of hair, but I have at least as much as I did when I was 30, and maybe even as much as I did when I was 25.

LED hair regrowth treatment is not for everyone. If the top of your head has been rendered completely smooth, it's very unlikely to make any difference. But if you have dormant follicles, they can be enlivened by the use of specific red-light wavelengths that stimulate those follicles through increased blood flow to the scalp. Results can take up to six months, but after eight weeks, the difference is noticeable enough to merit review.

I agreed to test the FDA-cleared GroWell, which sits in the middle of the price range at $550. It contains a total of 63 diodes, including 24 lasers and 39 LEDs. Beyond its attractive price point, comfortably between sketchy drop shippers and well-marketed products that cost nearly as much as the top-end MacBook Pro, the GroWell stands out for offering treatment at a level supported by clinical research without an overkill approach that can be counterproductive.