What Is Laser Therapy for Hair? A Look at a 2009 Laser Comb Study

What is laser therapy for hair?

Low-level laser therapy shines low-power light on the body. The authors explain that this kind of light has been studied for decades in wound healing, and that early work in mice was linked to hair growth. They write that how it might act on hair isn't fully understood. The authors' working idea is that the light may encourage cell growth in hair follicles and help follicles affected by pattern hair loss get back to a normal growth cycle.

The comb in this study gives off red laser light (655 nanometers) in nine beams, the authors report. Its teeth part the hair as you comb, so the light can reach the scalp.

How was the study set up?

In this study, men at four U.S. sites were randomly assigned, two to one, to the laser comb or a sham comb. The sham looked the same but used an ordinary incandescent bulb instead of a laser. The study was double-blind, so neither the men nor the study team knew who had which device. An evaluator who didn't know which device each man used counted hairs in a small, tattoo-marked circle on the crown, using close-up photos taken at the start and at the end of the study.

What did the study find?

• Hair counts: in the measured patch, the average hair count rose by about 20 hairs per square centimeter in the laser group and fell by about 8 in the sham group, the authors report. They also report that about 86% of men using the laser comb had a rise of more than 5 hairs per square centimeter, versus 5% of men using the sham.

• How men rated it: men using the laser comb rated their own regrowth higher on a questionnaire than men using the sham, according to the authors.

• What investigators saw: ratings from overview photos showed no meaningful difference between groups, the authors report. They note these ratings didn't line up with the hair counts, and they question how reliable overview photos are for judging hair.

• Side effects: the authors report no serious side effects. They list eight mild cases of tingling or hives that were possibly linked to the device, with no significant difference between groups.

• Limits: this was one 26-week study in 123 men, ages 30 to 60, and the device maker sponsored it, according to the publication.

What this means for you

The authors call for studies in other types of hair loss and for research into how laser light acts on hair follicles.

Beyond the Study: this is one study, in men, from 2009. If you're curious about light-based devices, a board-certified dermatologist can help you decide whether one fits your type of hair loss.

FAQs

Can women use laser therapy for hair loss? This study included only men. The authors note it was limited to men at the FDA's suggestion and that a similar study in women was planned, so this paper can't speak to results in women.

For the full findings and methods, read the full publication: HairMax LaserComb Laser Phototherapy Device in the Treatment of Male Androgenetic Alopecia: A Randomized, Double-Blind, Sham Device-Controlled, Multicentre Trial.

Read the full publication → Leavitt M, Charles G, Heyman E, Michaels D. HairMax LaserComb Laser Phototherapy Device in the Treatment of Male Androgenetic Alopecia: A Randomized, Double-Blind, Sham Device-Controlled, Multicentre Trial. Clin Drug Investig. 2009;29(5):283–292.

Disclosure: Dr. Matt Leavitt, the lead author, is a co-founder of Xtressé. The study was sponsored by Lexington International, LLC, the device maker. Co-author David Michaels was an employee of the company, Dr. Leavitt was a retained consultant and medical advisor to it, and Dr. Glenn Charles was a non-retained medical advisor. Other author disclosures are listed in the publication.

This article is for education only and is not medical advice. Talk with your healthcare provider about your own hair and scalp health.