Laser Caps for Thinning Hair: What the Trials Show Before You Spend

Laser caps and helmets for hair loss shine red light on the scalp from rows of small lasers or LEDs. You wear one at home on a schedule, with no pills and no daily scalp solution. Prices can run into the hundreds of dollars or more. Before you buy one, here is what the trials in women tested and what they asked of the people in them.

What the trials found

A 2014 trial in women. Researchers enrolled 47 women aged 18 to 60 with pattern hair loss and gave them either an active helmet or a look-alike helmet with ordinary red bulbs. Women used it at home every other day for 16 weeks, 25 minutes a session. Of the 42 who finished, the active group gained more hair in a small tattooed test patch than the sham group. No side effects were reported.¹

A 2019 trial in men and women. Forty people, half of them women, used a laser helmet or a sham helmet at home for 24 weeks. The laser group had greater gains in hair density and hair thickness. Some reported temporary shedding and an itchy scalp. The authors flagged the small size, no long-term follow-up and a sham device that may not have been a true blank.²

The American Academy of Dermatology (AAD)³ describes the regrowth from red light in hereditary hair loss as modest, and says it won’t regrow a full head of hair.³

What the studies don’t tell you

• How long results last. Neither trial followed people after the treatment period ended.¹²
• Whether your device matches. Each trial tested one design, with a set number of lasers, wavelength, session length and schedule. A cap you buy may differ in all of these.
• Whether you’ll keep it up. Every other day for four months is about 60 sessions.¹ Ask yourself whether that fits your week before you pay.

Check the type of hair loss first

The AAD says effective hair loss treatment starts with finding the cause. A dermatologist may order a blood test or scalp biopsy when a disease, deficiency, hormone change or infection is suspected.⁴ The laser trials enrolled people with pattern hair loss.¹² Sudden shedding, patchy loss, or a scalp that’s red, scaly or sore needs a diagnosis before a device.

Before you buy

1. Look up the clearance. The AAD advises choosing an FDA⁵-cleared device.³ Clearance through the FDA’s 510(k) pathway means the device was found substantially equivalent to one already on the market. You can search the FDA’s 510(k) database by maker or device name.⁵
2. Check your medicines. The AAD advises skipping red light therapy if you take medicine that increases light sensitivity, or have a condition such as lupus that light worsens.³
3. Read the return policy. If the trials needed four to six months of use, a 30-day return window doesn’t give you time to judge.¹²
4. Ask about combining. If you already use or are considering minoxidil or a prescription treatment, ask your dermatologist whether a cap adds enough to justify the cost.

Try: “I’m thinking about a laser cap for thinning at my part. What type of hair loss do I have, and would a cap be worth it on top of what you’d recommend?”

Hair, Everywhere includes a monthly Hair Log. Use it to record your sessions and take dated photos of your part in the same light, so you can see after four to six months whether the cap is earning its price. See the book.