Does Red Light Therapy Work for Hair Loss?
Yes, in men. This systematic review and meta-analysis of randomized controlled trials found that low-level laser light therapy was superior to placebo in men with androgenetic alopecia. This is a review of existing trials, not a new trial. The authors ran five separate meta-analyses: low-level laser light therapy in men, 5% minoxidil in men, 2% minoxidil in men, 1 mg finasteride in men, and 2% minoxidil in women. All five treatments beat placebo (p < .00001). Low-level laser light therapy was analyzed only in men. In women, the treatment with the evidence behind it here is 2% minoxidil.
Red light therapy, also known as low-level laser therapy (LLLT) or photobiomodulation, uses light delivered to the scalp as a treatment for pattern hair loss. Devices like the HairMax LaserComb are FDA-cleared, alongside the FDA-approved medications minoxidil and finasteride. Those three are the only treatments the FDA recognizes for androgenetic alopecia.
Androgenetic alopecia, commonly known as male pattern hair loss, is mediated by dihydrotestosterone, the potent form of testosterone.
What the Research Shows
The researchers searched PubMed, Embase, and Cochrane up to December 2016, with no lower limit on the year, and included only randomized controlled trials rated good or fair quality under the US Preventive Services Task Force quality assessment process. The trials compared nonsurgical treatments for androgenetic alopecia against placebo. The outcomes assessed were hair density, hair thickness, hair growth defined by an increased anagen to telogen ratio, and subjective global assessments by patients and investigators.
Five groups of studies were pooled: low-level laser light therapy in men, 5% minoxidil in men, 2% minoxidil in men, 1 mg finasteride in men, and 2% minoxidil in women. Every one of them was superior to placebo at p < .00001. Other treatments were left out because the data needed to pool them were lacking. The authors flag high heterogeneity across most of the included studies as a limitation. Their conclusion is that minoxidil, finasteride, and low-level laser light therapy promote hair growth in men with androgenetic alopecia, and that minoxidil is effective in women.
Dr. Kumar’s Take
Hair loss is one of those topics that people often feel embarrassed to bring up with their doctor, and when they do, the options have traditionally been limited to medications that come with side effects. Finasteride can affect sexual function. Minoxidil has to be applied daily and can irritate the scalp. Low-level laser light therapy is a device, not a drug, and for men it now has pooled randomized trial evidence behind it, which is more than most of what gets sold for hair.
I want to be precise about who that applies to. The laser evidence in this review is in men. For women, the treatment that cleared the same bar here is 2% minoxidil. That does not mean a laser device cannot help a woman, it means this paper does not tell me that it does, and I am not going to borrow a result from one population and hand it to another. If you are a woman with pattern hair loss, minoxidil is where the evidence in this review sits.
The other thing I would say to anyone reading this: the comparison in every one of these trials was against placebo, not against each other. So this tells you these treatments work. It does not rank them.
How Light Therapy Stimulates Hair Growth
Hair follicles cycle through a growth phase, anagen, and a resting phase, telogen. One of the outcomes this review used to define hair growth was an increased ratio of anagen to telogen hairs, meaning more follicles actively growing relative to those at rest. In androgenetic alopecia, driven by dihydrotestosterone, that balance shifts the wrong way. Low-level laser light therapy delivers light energy to the scalp rather than acting on hormones, which is a different route to the same endpoint than finasteride or minoxidil take.
Practical Takeaways
- Low-level laser light therapy was superior to placebo in men with androgenetic alopecia in this pooled analysis of randomized controlled trials.
- The evidence for women in this review is for 2% minoxidil. Laser therapy was not meta-analyzed in women here.
- Minoxidil and finasteride are FDA-approved and the HairMax LaserComb is FDA-cleared. These are the only treatments the FDA recognizes for this condition.
- The included trials all compared treatment against placebo, so the review supports these treatments individually but does not rank one above another.
- High heterogeneity across the included studies is a real limitation, and it should temper how firmly you read any single pooled result.
FAQs
How long does it take to see results from laser hair therapy?
This review does not report a time course, so I cannot give you one from it. Hair growth is slow by nature, and the trials it pooled measured outcomes like hair density, thickness, and the ratio of growing to resting hairs at the end of treatment periods. If you start a device, judge it over months rather than weeks, and be consistent with it.
Do I need a prescription for a laser hair device?
The HairMax LaserComb is FDA-cleared rather than FDA-approved, a different regulatory pathway than the one minoxidil and finasteride went through. Clearance is not the same standard as approval. My advice is to look for devices that have actually been tested in randomized trials, since those are the ones a review like this can pool.
Can women use red light therapy for hair loss?
This review cannot answer that. Low-level laser light therapy was meta-analyzed only in men. The single treatment analyzed in women was 2% minoxidil, and that is what the authors conclude is effective in women with androgenetic alopecia. Women do get pattern hair loss, and it is mediated by the same hormone, but the laser result here does not extend to them on the strength of this paper.
Bottom Line
This meta-analysis supports minoxidil, finasteride, and low-level laser light therapy for promoting hair growth in men with androgenetic alopecia, and minoxidil in women. All five pooled comparisons beat placebo at p < .00001. Read it as a review of randomized trials rather than a single study, keep the high heterogeneity in mind, and match the treatment to the population it was actually studied in.
