How Laser Hair Growth Caps and Combs Work to Fight Hair Loss

If you're wondering whether these laser devices for hair loss are worth the investment, here's what you should know.

Hair Health Hotline: Do laser caps and combs really promote hair growth?
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Hair Health Hotline is your direct access to dermatologists, trichologists, hairstylists, and other beauty pros. Each story in this series tackles a common hair or scalp concern and offers science-backed solutions to care for your strands.

You've seen the ads: Someone's wearing a slightly ill-fitting baseball cap or a helmet that looks straight out of a '70s sci-fi film. But they're actually using a laser hair growth cap, a type of device designed to restore thinning or sparse hair to its former glory. With the number of hair loss solutions swirling on the internet, you might be wondering if the marketing is actually worth buying into — literally.

Allow William Yates, M.D., F.A.C.S., a Chicago-based board-certified hair loss surgeon and founder of Dr. Yates MD Hair + Science, to cut to the chase. Below, he shares the important details on laser hair caps (and their handheld counterparts, laser combs) and whether they're worth trying.

Q: What's the deal with those laser hair caps? Can they actually help with hair loss, and are they worth the money?

A: Over time, a laser hair growth cap or comb can help restore healthy hair growth, whether you're experiencing excessive shedding or thinning. The red light emitted by the devices (which include Capillus caps, the iRestore Hair Growth Helmet, and Hairmax caps and combs, to name a few) targets hair follicles to promote healthy hair growth. You may have heard the technology referred to as low-level light therapy (LLLT).

Remember learning about the visible spectrum in science class? You might recall that it's the spectrum of light that's visible to the human eye, and that different colors of light have different wavelengths. "The spectrum of red light has a wavelength of about 640 to 680 nanometers," says Dr. Yates. "These devices amplify that signal. These laser beams at this wavelength penetrate your skin to reach the hair follicle, which is about three millimeters below the skin."

That can be an exciting prospect, since red light seems to have hair growth-boosting effects. "Scientists have found that when you isolate the red light out of the visible light spectrum and kind of amplify it that it can stimulate hair growth," says Dr. Yates. "The light energy goes to the root of the hair and actually stimulates the hair follicle to make more energy, more nutrients that make the hair follicle to produce better quality hair over time." I.e. if you have hair follicles that have started producing fine, fragile strands, light therapy might help the follicles produce stronger, thicker strands once again. (

The hair growth laser caps and combs might also help with excessive hair shedding. Strands of hair have a lifecycle that consists of growth, resting, and shedding phases, explains Dr. Yates. "Hair growth is a continuous thing — you shed hair and you grow hair," he says. "You only have a problem when you start shedding more than you grow back. The laser is thought to shift [hair follicles from] that shedding phase to the growing phase."

Hair Health Hotline: Do laser caps and combs really promote hair growth?
Andrew van Tilborgh

Are Laser Hair Growth Devices Actually Effective?

Laser caps and combs aren't a gimmick in Dr. Yates' eyes. It's the hair loss solution that he recommends most often apart from hair transplants and the medications minoxidil and Propecia, he says. "I think in the grand scheme of things, the laser is better than anything else you can get on the internet, by far," says Dr. Yates.

The devices are Food and Drug Administration (FDA)-cleared, he points out. (In case you need to brush up on your FDA lingo, if something's FDA-cleared, that means that the FDA has determined that the product is "equivalent" to a similar existing "FDA-approved" product that's already been deemed "safe and effective.")

The laser devices seem to be effective for treating all types of hair loss, with the exception of types of scarring alopecia, says Dr. Yates. "Scarring alopecia is usually referred to as an autoimmune problem where the body attacks the hair follicle and destroys it," he says. "It's fairly prevalent, and the laser devices don't work well at all for scarring alopecia. The hair follicle is destroyed beyond repair, so even the red light can't help it."

While in-office laser treatments for hair loss exist, some of today's at-home devices are likely just as effective, says Dr. Yates. "Now that companies have made caps that give you the same energy and number of lasers that you'd have at the office, there's really no difference," he says. "There was a time when the equipment in the offices had more energy than what you could buy. But now there's really no difference between going to a doctor's office and sitting under these hoods they used to have vs. some of the caps that you can buy now." That said, comb devices generally don't give off the same amount of energy as the caps and so they may not produce as strong results, he notes.

How to Use a Laser Hair Growth Cap Or Laser Comb

One thing to keep in mind: To maintain results from a laser hair growth cap or comb, you'll have to commit to continuous use of your device. "Anything with hair is going to take at least two months to show any results," says Dr. Yates. To give you an idea of what you'd be signing up for, some devices require three 20-minute sessions per week, he says. And that's a major reason why many people prefer a cap to a laser comb. While the former is hands-free, the latter can end up giving you quite the arm workout, since you have to continuously run it along your scalp.

"If you're all in and you do it correctly, at two months, people normally say, 'Hey, my hair is not shedding as much in the bathtub, in the shower, I don't see as much hair, my hair is better,'" says Dr. Yates. "By four months, patients usually report that they're actually seeing more hair growth, people are making comments, so on and so forth. After that four-month period, you still have to continue...It's a lifelong commitment if you're going to use it." (

Despite what you might think when you hear the word "laser," you won't feel any pain when using a laser hair growth cap or comb. The types of lasers in these devices are referred to as cool lasers, meaning they don't give off heat and you won't risk burning yourself, says Dr. Yates.

They can also cost a cool $1000+, so price can certainly be a prohibitive factor. But if you're prepared to shell out the money and commit to using a laser hair growth device regularly, you might find that the results are worth it.

Have a hair health question you want answered? Send your Q to for a chance to have it featured in a future installment of Hair Health Hotline.

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